Chapter IV: Part 4

KANSAS: _Anderson_: KU 52286-87, 3-1/4 mi. E, 1/2 mi. N Colony. _Atchison_: UMMZ 66939-41, Atchison. _Barber_: KU 17728, 4.5 mi. S Sun City; KU 41379, 41742, 6 mi. N, 3.5 mi. E Sharon; USNM 100580, Medicine River, 1 mi. S Lake City. _Cherokee_: KU 1323, Galena. _Comanche_: KU 18385, 3-4 mi. SE Arrington. _Cowley_: UMMZ 75963, USNM 90441-44, 91022, 100529-30, "near" Winfield. _Doniphan_: KU 1943, 1952-54, Doniphan Lake. _Douglas_: KU 1955-56, Wakarusa River; KU 40176-77, Kansas River at Lawrence. _Franklin_: KU 3290. _Hamilton_: KU 2990, Syracuse. _Harper_: KU 18159, 1 mi. N Harper. _Kingman_: USNM 95261, 2 mi. E Calista. _Labette_: KU 3339. _Lane_: KU 3738-41, Pendennis. _Logan_: KU 16531, Smoky Hill River, 3 mi. SW Elkader. _Meade_: KU 40210, Crooked Creek, 12.5 mi. S, 1-1/4 mi. W Meade. _Montgomery_: KU 3731-32, Independence; KU 50856, Cherryvale Lake. _Neosho_: UMMZ 69294, Caneville Creek, 32 mi. N. Parsons, Labette County. _Osage_: KU 3294-96, Appanoose Creek. _Pratt_: KU 15931-32, 15934, State Fish Hatchery "near" Pratt. _Riley_: KU 48239, McDowell Creek, WSW Manhattan; UMMZ 64434, "near" Manhattan. _Russell_: KU 3289. _Sedgwick_: UMMZ 95363-65, Wichita. _Shawnee_: USNM 123446, Kansas River at Topeka. _Stafford_: KU 3758, Little Salt Marsh; KU 41743, 13.5 mi. N, 6 mi. E Stafford. _Trego_: KU 2757, 3769, Smoky Hill River, 10 mi. N (NNE) Utica, Ness County; KU 51517, Saline River, 5 mi. N, 1/2 mi. E Wakeeney. _Wilson_: KU 56744-45, Verdigris River, 1 mi. S Altoona. _Woodson_: KU 55295, Neosho River, 1/2 mi. E, 1-1/2 mi. S Neosho Falls. _County unknown_: USNM 51529.

LOUISIANA: _Catahoula_: TU 12629, Ouachita River, 4 mi. N Harrisonburg. _Claiborne_: TU 13080, Caney Lake "near" Summerfield. _Concordia_: KU 50849, Tensas River at Clayton; TU 16524 (3), USNM 012349, Lake Concordia; USNM 99865, Red River "near" Shaw. _East Carrol_: TU 827-30, 905, 5644-45, Lake Providence. _Grant_: TU 12735, Big Creek at Fishville, "near" Pollock. _Jefferson_: TU 5592-98, 7184, 10741, 10171, Mahogany Pond. _Lafourche_: TU 7105, 7132, 7216, 7501, 7505-07, 10087 (14), 11828-29, 11912, 11983 (2), 12123-28, 13502, 13679 (8), 13753 (22), 13766.2, Bayou Lafourche at Raceland. _Morehouse_: USNM 11631 (2), Mer Rouge. _Natchitoches_: USNM 100420, Cane River "near" Natchitoches. _Orleans_: TU 16169 (3), Audubon Park, New Orleans; USNM 029310, "near" New Orleans. _Ouachita_: TU 12916, 12954, 12970-71, 13019, 13025, Bartholomew Bayou at Sterlington; TU 5988, Monroe. _Pointe Coupee_: TU 153, 156-59, 165, 5484, 5513, 5518-19, 5646, 5648, 5651, USNM 100202-12, False River at New Roads. _Rapides_: TU 14040, Red River at Rapides. _Richland_: OU 25082. _St. Bernard_: TU 16170, Delacroix Island. _St. Charles_: TU 4539, 4579, 5224, 5990, 11928 (12), 13698 (16), Bayou Gauche between Paradis and Des Allemands; TU 5863, 11580, Bonnet Carre Spillway at Norco. _Tensas_: TU 5762, Lake St. Joseph near Newellton. _Union_: USNM 138946, Meridian Creek, 1 mi. E Conway; USNM 138947, Ouachita River, Alabama Landing. _Parish unknown_: MCZ 1622, Lake St. John (Concordia or Tensas Parish); USNM 029266, Louisiana?

MINNESOTA: _Hennepin_: AMNH 4759-60, Fort Snelling. _Lesueur_: KU 46742-43, Waterville, Lake Tetonka. _Winona_: USNM 59263-66, Homer.

MISSOURI: _Carter_: UMMZ 70737, "near" Van Buren. _Chariton_: UI 17509, Triplett. _Franklin_: USNM 55689. _Gasconade_: UMMZ 95900, Bourbeuse Creek, 8 mi. S Owensville. _Jefferson_: USNM 95405, Glaize Creek. _Lewis_: USNM 59279-80, Canton. _Miller_: UMMZ 91929, Barren Fork Tavern Creek, 5 mi. NW Iowna. _Newton_: UMMZ 82822, Shoal Creek, 12 mi. W Momit. _Phelps_: UMMZ 91930, Bourbeuse River, 10 mi. N St. James. _Reynolds_: CNHM 35392, Black River at Warner Bay Spring; USNM 55688. _Ripley_: UMMZ 90435. _Shannon_: INHS 6223, Alley Spring State Park. _St. Charles_: USNM 93089-94, Dardenne Creek, St. Peters. _St. Louis_: USNM 55685-87, Mississippi River at St. Louis. _Stone_: USNM 55684. _Washington_: USNM 55690. _Wayne_: UI 16554, Sam A. Baker State Park; UMMZ 95879, St. Francis River at Lodi. _County unknown_ (Wayne or Butler): UMMZ 83264, Clark National Forest, St. Francis River.

MONTANA: _Big Horn_: USNM 54421, Crow Agency. _Roosevelt_: USNM 58, Fort Union (locality reads "Yellowstone, Fort Union"; probably the Yellowstone River near Fort Union). _Wheatland_: UMMZ 92005, Musselshell River near Shawmut. _Yellowstone_: USNM 14535, Custer.

OKLAHOMA: _Alfalfa_: OU 9316, 2 mi. S Cherokee. _Cleveland_: OU 22973, Norman. _Delaware_: UMMZ 81476, Spavinaw. _LeFlore_: OU 16802, 1.5 mi. E Zoe. _Osage_: UMMZ 89628, Big Hominy Creek. _Pottawatomie_: OU 25175, 5 mi. SW Shawnee. _Rogers_: OU 7317, Verdigris River, 5 mi. W Claremore; UMMZ 81473-74, near Garnett, Tulsa County; UMMZ 81475, 4 mi. NE Inola. _Sequoyah_: OU 9008, 2 mi. NE Gore; TU 13885, Little Vian Creek, 1 mi. E Vian. _Texas_: OU 5005, 5 mi. SE Guymon. _Tulsa_: TU 17061, Bird Creek "near" Skiatook, Osage County. _Woods_: CHNM 11809, Waynoka; OU 9432, 2.5 mi. W Waynoka; OU 9579, 9581-82, 1 mi. S Waynoka.

TEXAS: _Hansford_: TTC 719, 10 mi. S, 2 mi. W Gruver. _Hutchinson_: TTC 1090, Carson Creek, Turkey Track Ranch.

WYOMING: _Goshen_: USNM 7648, Fort Laramie. _Weston_: UMMZ 78080, Beaver Creek.

NO DATA: CNHM 21687-88, 22925. SM 142 (locality of Waco, McLennan County, Texas, believed in error). USNM 7649, 11625, 19622-23, 36412 (Illinois River).

_Records in the literature._--ARKANSAS: _Benton_: (Dowling, 1957:37). _Chicot_: Lake Chicot. _Clark_: Terre Noir Creek, 13 mi. W Arkadelphia. _Garland_: Ouachita River, Mountain Pine (Conant and Goin, 1948:7). _Hempstead_: _Jefferson_: (Dowling, _loc. cit._). _Lawrence_: Black Rock (Dellinger and Black, 1938:46). _Madison_: _Scott_: _St. Francis_: (Dowling, _loc. cit._). _Washington_: near Greenland (Dellinger and Black, _loc. cit._).

COLORADO: _Boulder_: Boulder Creek, E Boulder; Boulder Creek, 6 mi. S and 1 mi. E Longmont. _Larimer_: Cache la Poudre River. _Logan_: 8 mi. NE Sterling. _Morgan_: Platte River "near" Fort Morgan. _Otero_: Purgatoire River at Higbee. _Prowers_: Arkansas River at Lamar. _Weld_: Poudre River "near" Greeley; Evans. _Yuma_: Bonny Dam, Republican River (Maslin, 1959:24-25).

IOWA: _Dickinson_: Little Sioux River, Okoboji Twp. (Blanchard, 1923:24). _Story_: Skunk River, 5 mi. NNE Ames (Conant and Goin, 1948:9).

KANSAS: _Allen_: Petrolia (KKA). _Barber_: 7 mi. S Sun City. _Butler_: 3 mi. SE Augusta (Burt and Hoyle, 1934:198). _Chase_: 10 mi. SW Olpe; 7 mi. SW Saffordville (Breukelman and Smith, 1946:112). _Cherokee_: tributary of Spring River, 1 mi. N Riverton (Hall and Smith, 1947:451). _Coffey_: (Smith, 1956:160, symbol on map). _Cowley_: 11 mi. SE Winfield (Stejneger, 1944:55). _Crawford_: Pittsburg (Hall and Smith, _loc. cit._). _Doniphan_: "near" Geary (Linsdale, 1927:81). _Elk_: (Smith, _loc. cit._). _Ellis_: Big Creek (Brennan, 1934:190); Ellis (Conant and Goin, 1948:2). _Franklin_: Middle Creek, SE part of county (Gloyd, 1928:135). _Greenwood_: (Stejneger, _op. cit._:54). _Leavenworth_: Missouri River "near" Fort Leavenworth (Brumwell, 1951:208). _Lyon_: 5 mi. E Emporia (Breukelman and Smith, _loc. cit._). _Marion_: (Smith, _loc. cit._). _Meade_: Meade County State Park, _ca._ 13 mi. SW Meade (Tihen and Sprague, 1939:505). _Ness_: 5.5 mi. NW Ness (Breukelman and Smith, _loc. cit._). _Osage_: Marais des Cygnes River; Long and Jordan Creeks (Clarke, 1958:21). _Reno_: 6 mi. E Turon. _Sedgwick_: 2 mi. NE Cheney (Burt, 1935:321). _Sheridan_: State Lake 7 mi. NE Quinter, Gove County (Breukelman and Smith, _loc. cit._). _Wabaunsee_: Dragoon Creek at Harveyville (Clarke, 1956:215). _Wallace_: (Burt, 1933:208). _Wilson_: Fall River, 1/2 mi. S Neodesha (Clarke, _loc. cit._).

MINNESOTA: _Anoka_: _Benton_: _Chisago_: (Breckenridge, 1944:184, symbols on map). _Crow Wing_: (Breckenridge, _op. cit._:185). _Dakota_: (Hedrick and Holmes, 1956:126). _Goodhue_: (Breckenridge, _op. cit._:184, symbol on map). _Hennepin_: Minneapolis; Lake Minnetonka (Breckenridge, _op. cit._:187); 5 mi. N. Minneapolis (Breckenridge, 1955:5). _Houston_: Root River near Hokah. _Lesueur_: Lake Washington (Hedrick and Holmes, _loc. cit._). _Meeker_: Swan Lake (Breckenridge, 1957:232). _Pine_: (Breckenridge, 1944:185). _Ramsey_: _Rice_: _Sherburne_: _Stearns_: (Breckenridge, _op. cit._:184, symbols on map). _Washington_: just north of Stillwater (Hedrick and Holmes, _loc. cit._). _Winona_: Winona (Breckenridge, _op. cit._:187). _Yellow Medicine_: (Breckenridge, _op. cit._:185). _County unknown_ (Goodhue or Wabasha): Lake Pepin (Breckenridge, _op. cit._:184).

MISSOURI: _Boone_: east of Ashland (Henning, 1938:92). _Jackson_: Missouri River "near" Atherton (Anderson, 1942:219). _Jefferson_: Mississippi River "near" mouth Glaize Creek at Sulphur Springs; Glaize Creek at Barnhart (Boyer and Heinze, 1934:199). _St. Clair_: Osage River "near" Osceola. _Vernon_: Marmaton River, 7 mi. N Moundville (Conant and Goin, 1948:9).

MONTANA: Yellowstone River (Conant and Goin, 1948:9).

NEBRASKA: _Adams_: 1 mi. N Ayr (Hudson, 1942:101). _Dawson_: 2 mi. SE Gothenburg (Gehlbach and Collette, 1959:142). _Franklin_: 2 mi. SW Naponee. _Gage_: 1 mi. W Barnston. _Hitchcock_: 3 mi. E Stratton. _Holt_: Elkhorn River "near" Atkinson. _Lancaster_: Lincoln (Hudson, _loc. cit._). _Lincoln_: 1 mi. S Sutherland (Gehlbach and Collette, _loc. cit._). _Red Willow_: 14 mi. NW McCook. _Richardson_: 2 mi. S Rulo. _Wheeler_: 2 mi. W Ericson (Hudson, _loc. cit._).

OKLAHOMA: _LeFlore_: Wister (Conant and Goin, 1948:9); Shady Pointe (KKA); Poteau River, 6.5 mi. W Heavener (Trowbridge, 1937:301). _Tulsa_: Arkansas River "near" Tulsa (Force, 1930:38).

WYOMING: _Goshen_: Platte River (Conant and Goin, 1948:10).

=Trionyx spinifer asper= (Agassiz)

Gulf Coast Spiny Softshell

Plates 37 and 38

_Aspidonectes asper_ Agassiz, Contr. Nat. Hist. United States,
1(Pt. 2):405; 2(Pt. 3):pl. 6, fig. 3, 1857.

_Trionyx spinifer asper_ Schwartz, Charleston Mus. Leaflet,
No. 26:17, pls. 1-3, map 2, May, 1956.

_Platypeltis agassizii_ Baur, Amer. Nat., 22:1121, 1888.

_Type._--Lectotype, MCZ 1597; alcoholic female; locality designated as Pearl River, Columbus, Marion County, Mississippi; received from Mr. Winthrop Sargent of Natchez, Mississippi.

_Range._--Southeastern United States except peninsular Florida from the Florida Parishes of Louisiana east to southern North Carolina; Gulf Coast drainage including that of Lake Pontchartrain, Louisiana, eastward to the Apalachicola River system, and Atlantic Coast drainage including that of the Altamaha River in Georgia northward to the Pee Dee River drainage in South Carolina (see map, Fig 19).

_Diagnosis._--Juvenal pattern of black ocelli and spots, and two or more black, interrupted, lines paralleling rear margin of carapace; pale postocular and postlabial stripes often united on side of head; length of plastron short.

_Description._--Plastral length of smallest hatchling, 2.9 centimeters (USNM 134244); of largest male, 13.2 centimeters (TU 17117); of largest female, 27.0 centimeters (TU 13474).

Blackish marginal rings on carapace number two, three or four posteriorly, but decrease in number anteriorly; segments of marginal rings may extend to nuchal region; marginal rings increasingly interrupted inwardly; pattern of hatchlings having well-defined marginal rings that are not extensively interrupted (often males), or having marginal rings broken into small segments or series of dots, and pale outer margin of carapace marked by ill-defined, hazy, inner border (often females); conspicuous marginal rings often lacking on hatchling females; pale rim of carapace not four or five times wider posteriorly than laterally; carapace having blackish dots, spots, small ocelli or a combination thereof; marks on carapace of slightly varying sizes, some occasionally barlike (usually males); some hatchling females showing pale, irregular blotching on carapace, often characterized by small lichenlike figures superimposed on blackish dots.

Striping on snout variable; pale, dark-bordered stripes usually unite in front of eyes and form right or acute angle; medial dark borders of pale stripes on snout not joined anteriorly, broken into segments or dots, reduced to single median line, united to form straight line connecting anterior margins of orbits (usually with slight medial indentation), or absent; pale postocular and postlabial stripes often joined, relationship variable and on either side of head; side of head with or without dark markings, sometimes a pale subocular blotch bordered below by a dark line; pattern on dorsal portions of soft parts of body contrasting, less so on limbs of hatchlings; pattern of irregular dark marks, dark streaks usually coincident with digits; longitudinal streaks often occur on neck; elongate tail of adult males usually having well-defined, dorsolateral, pale bands with dark lower border more diffuse than upper border.

Underparts whitish often with dusky markings on rear of carapace or in region of bridge; blackish marks often on webbing and portions of soles and palms, and chin and throat.

Small conical tubercles along anterior edge of carapace on adult males; remnants of juvenal pattern usually present on carapace of large females; conical or knoblike tubercles on anterior edge of carapace of large females; accessory knoblike tubercles in nuchal region (a paravertebral pair usually most prominent), and posteriorly in middle of carapace on large females.

Ontogenetic variation in PL/HW, mean PL/HW of specimens having plastral lengths 7.0 centimeters or less, 3.87, and exceeding 7.0 centimeters, 4.94; ontogenetic variation in CL/CW, mean CL/CW of specimens having plastral lengths 8.5 centimeters or less, 1.11, and exceeding 8.5 centimeters, 1.16; mean CL/PCW, 1.71; mean CL/PL, 1.45.

_Variation._--The sex of some hatchlings can be distinguished by the pattern on the carapace (see Plate 37 for different patterns), but the sex of many hatchlings cannot be distinguished on the basis of pattern.

In the early stages of this study, I thought that the pattern on the carapace differed in eastern and western populations, and that the zone of intergradation was in Alabama. Adult males from the Tombigbee-Alabama river drainage and westward were noted to have blackish spots (some slightly ocellate) intermixed with few, if any, smaller blackish dots, whereas the adult males from east of the Tombigbee-Alabama river drainage had many small, black dots intermixed with slightly larger, mostly ocellate marks (see Plate 38, left, top and bottom, for contrast); also, hatchlings from western populations were never observed to have four marginal rings. On the basis of pattern, I would have thought that the individual having many ocelli, that lacks correct locality data and that is photographed by Stejneger (1944:Pl. 26), came from Georgia or South Carolina; but, the pattern (_op. cit._:Pl. 27) of a specimen, probably an adult male, from South Carolina, resembles the pattern on adult males from Louisiana. The differences noted above are probably due to individual variation rather than geographic variation.

Color notes taken from life of a freshly-killed adult male (TU 16071, Louisiana) are: carapace olive, spots blackish, outer rim buff; top of head olive, postocular and postlabial stripes yellow with blackish borders, stripes on snout buff with blackish borders; dorsal ground color of soft parts of body pale olive-green, larger marks blackish, ground color laterally toward juncture of pattern and immaculate undersurface, and toward insertions of neck and limbs becoming yellowish; webbing on hind limbs having reddish tinge; dorsolateral bands on tail yellow with blackish borders; undersurface whitish; chin and throat olive-green with blackish marks; becoming buff then whitish posteriorly.

Occasional specimens have only one definite dark line paralleling the rear margin of the carapace. Schwartz (1956:16) reported that Charleston Museum No. 55.159.26 has only one solid line at the margin of the carapace, and I received an adult male (KU 47120) reported to have come from the Pearl River that is aberrant in not having more than one dark marginal line. USNM 95191, a large stuffed female from the Pearl River is mentioned by Stejneger (1944:59, Pl. 17) as having marks that "assume the form of short lines parallel with the submarginal ring"; I examined this specimen and noted that it had only one dark marginal line. Stejneger (_op. cit._:64) mentioned another from the Pearl River drainage, and Crenshaw and Hopkins (1955:20) wrote that some individuals from Georgia have only one dark marginal line. Presumably MCZ 1606 (now in the Albany Museum) recorded by Stejneger (_op. cit._:52) as _Amyda s. spinifer_ from Columbus, Georgia, is another specimen.

Some skulls of soft-shelled turtles from streams of the Atlantic Coast drainage, including the skull of the holotype of _Platypeltis_ (= _Trionyx_) _agassizi_ Baur (MCZ 37172, Pl. 54), show at least two differences from other skulls of _asper_ and from those of other subspecies of _T. spinifer_. Figure 20 shows that skulls of _agassizi_ tend to have slightly smaller internal choanae (ratio IC/MB) than those of _T. spinifer_ and _T. ferox_; there is seemingly little difference between skulls of _ferox_ and _spinifer_, and little, if any, ontogenetic variation. Figure 21 shows that most skulls of the _agassizi_-form that exceed 43.0 millimeters have a more expanded, alveolar surface of the maxilla than skulls of _spinifer_ of approximately the same size; most skulls exceeding a basicranial length of 43.0 millimeters, and certainly all skulls exceeding 50.0 millimeters are those of females. Stejneger (1944:Pl. 30) also has provided photographs of a skull of the _agassizi_-form. It is of interest that of the 12 _agassizi_-form skulls (MCZ 37172; USNM 8708, 029034, 51981, 66859, 71681, 91282, 91310-11, 92521, 92583-84) that I examined some resemble _ferox_ (Neill, 1951:9) in having the alveolar surfaces of the jaws broadened, and the greatest width at the level of the quadratojugal (Table 3, Plate 54); also, the localities of all 12 skulls are within the geographic range of _ferox_. Skulls of _ferox_, however, have conspicuously broadened alveolar surfaces of the jaws only when they exceed in length the largest skulls of _agassizi_. The differences of skulls of the _agassizi_-form possibly reflect isolation in the Atlantic Coast drainage, and an adaptation in feeding habits. So far as I can ascertain, individuals occurring in rivers of the Atlantic Coast drainage in Georgia and South Carolina (referable to _agassizi_) do not differ consistently in external characters from individuals of _T. s. asper_ that occur westward in the Apalachicola drainage.

_Comparisons._--_Trionyx s. asper_ can be distinguished from all other subspecies of _T. spinifer_ by usually having more than one black line paralleling the rear margin of the carapace. This character and the frequent fusion of the postlabial and postocular stripes on the side of the head distinguish _asper_ from _spinifer_ and _hartwegi_. _T. s. asper_ differs from _pallidus_, _guadalupensis_ and _emoryi_ in having blackish spots and ocelli on the carapace, and lacking whitish dots or tubercles. _T. s. asper_ resembles _spinifer_, _hartwegi_ and _pallidus_ but differs from _guadalupensis_ and _emoryi_ in having conical tubercles along the anterior edge of the carapace in large females. For additional differences see accounts of other subspecies.

Of the subspecies of _T. spinifer_, _asper_ has a proportionately wide head that is closely approached in the subspecies _guadalupensis_ and _emoryi_; _T. s. asper_ differs from _guadalupensis_ and _emoryi_ in having a wider carapace, and resembles _hartwegi_ and _spinifer_, but differs from the other subspecies in having the carapace widest at a plane approximately one-half way back on the carapace. _T. s. asper_ differs from the other subspecies in having the shortest plastron.

_Remarks._--Stejneger (1944:72-74) has discussed the history of Baur's _Platypeltis agassizi_. Briefly, Agassiz's description of _Platypeltis ferox_ wherein he (1857:402) states that "The young ferox [Pl. 6, fig. 3] has two or three concentric black lines separating the pale margin ...," was applicable to _T. s. asper_. Agassiz mentioned also that the young of his _Aspidonectes asper_ (_op. cit._:406) "as in Platypeltis ferox, ... has ... two or three black lines separating the pale rim of the posterior margin, ..."; however, _A. asper_ was distinguished chiefly by the "... prominent warts of the bony plates (_loc. cit._)." Because the description of the pattern of _ferox_ resembled that of _asper_, the validity of _asper_ was not agreed upon by all workers. Boulenger (1889:245, footnote 1) referred to _asper_ as a species that required "... further investigation."

Baur (1888:1121) realized that Agassiz's description of _ferox_ was not that of _Testudo ferox_ Schneider, and regarded the description of Agassiz as applying to a new species, which he named _Platypeltis agassizii_; Baur (_op. cit._:1122) also recognized _asper_, referring it to the genus _Aspidonectes_. Baur designated a specimen from Georgia (the only individual seen by him) as the type of _agassizi_ (Stejneger, _op. cit._:73, footnote); this specimen is now MCZ 37172. Five years later (1893:218), Baur discussed generic relationships of trionychids, seemingly only on the basis of skulls (holotype of _agassizi_ not mentioned), and referred _agassizi_ to the resurrected genus _Pelodiscus_ Fitzinger, 1835, which was distinguished from the other two American genera that Baur recognized (_Platypeltis_ and _Amyda_) by having the "Posterior nares reduced in size by the inner and posterior extension of the maxillaries." Baur also transferred _asper_ to the genus _Platypeltis_, and restricted the type locality of that species to "Lake Concordia, La." (_op. cit._:220); the type locality of _agassizi_ was restricted to "Western Georgia" (_loc. cit._).

The name-combination, _Pelodiscus agassizi_, was not generally accepted. Hay (1892:144) and Siebenrock (1924:188) referred _agassizi_ to the genus _Trionyx_. Hay regarded _agassizi_ as a full species (see discussion by Stejneger, 1944:73), whereas Siebenrock considered it a subspecies of _spiniferus_; both authors regarded _asper_ as a synonym of _agassizi_. Neither _asper_ nor _agassizi_ was mentioned in the first three editions of the Check List of North American Amphibians and Reptiles (Stejneger and Barbour, 1917, 1923, 1933); the same authors in the fourth (1939:171, 172) and fifth editions (1943:212, 213) listed _agassizi_ as a full species, and _asper_ as a subspecies of _spinifera_. Stejneger (1944) used the same arrangement as set forth in the fourth and fifth editions of the Check List, and distinguished _agassizi_ on the basis of cranial characters, namely, the small size of the internal choanae, the greater width of the alveolar surface of the lower jaw, and the position of the suture between the palatine and basisphenoid relative to the posterior edge of the temporal fossa. Neill (1951:9) regarded the peculiarities of the _agassizi_-type skull as inconstant, but recognized _agassizi_ (and _asper_) as a subspecies of _ferox_. Crenshaw and Hopkins (1955) showed that _asper_ did not intergrade with _ferox_. Schwartz showed that _agassizi_ did not intergrade with _ferox_, and regarded _agassizi_ as a synonym of _T. s. asper_ (1956:17), but stated that _agassizi_ possessed "wider crushing surfaces on the maxillae than does _T. s. asper_, even when skulls of the same size and sex are compared" (_op. cit._:9).

The holotype of _Platypeltis agassizi_ (MCZ 37172) is a dried adult female consisting of shell, skull and limb bones; the carapace is approximately 300 millimeters long (Schwartz, _loc. cit._). I have examined only the skull of MCZ 37172 (Plate 54), and it is the largest of 12 _agassizi_-type skulls I have seen. The basicranial length is 72.5 millimeters, and the greatest width, which occurs at the level of the quadratojugals, is 52.9 millimeters. The _agassizi_-type skulls have been discussed under the subsection on variation.

The type locality of _T. s. asper_, Lake Concordia, Louisiana (lower Mississippi River drainage) as restricted by Baur (1893:220), is in an area of intergradation of three subspecies of _Trionyx spinifer_ where most individuals are not typical of _asper_. The syntypes, the designation of MCZ 1597 as a lectotype, and Pearl River, Columbus, Marion County, Mississippi, as the type locality have been discussed elsewhere (Webb, 1960).

The range of _T. s. asper_ overlaps that of _T. ferox_ in Georgia and South Carolina. The two species remain distinct in the area of overlap of their geographic ranges (Crenshaw and Hopkins, 1955:16; Schwartz, _op. cit._:5). _Trionyx s. asper_ intergrades with _T. s. hartwegi_ and _T. s. spinifer_ in the lower Mississippi Valley (Conant and Goin, 1948:11).

However, there are few specimens available that indicate intergradation of _asper_ with the _spinifer-hartwegi_ complex in the lower Mississippi River drainage; this may be due to the fact that _asper_ inhabits waterways that do not drain into the Mississippi River. Perhaps intergradation is more prevalent than the morphological basis that I have relied upon indicates; in any event, there are few specimens that have more than one dark marginal line (which is the only character that is unique for _asper_) from the lower Mississippi drainage. A young male (TU 11928.9) from Bayou Gauche between Paradis and Des Allemands, St. Charles Parish, Louisiana, has a pattern on the carapace resembling that of _asper_; several other small softshells (TU) are available from the same locality but none shows more than one dark marginal line. Another specimen (USNM 95192), a young female from a barrow pit of the Big Black River (Mississippi River drainage), Madison County, Mississippi, resembles _asper_ in having more than one marginal ring. Of three large females from Moon Lake, an ox-bow of the Mississippi River in Coatopa County, Mississippi (AMNH 5285-86, 5289), only 5289 shows evidence of two marginal lines. USNM 73669 (Greenwood, LeFlore County, Mississippi) also indicates intergradation in that the spots tend to be linear just inside the dark marginal line, but the specimen more closely resembles the _hartwegi-spinifer_ complex rather than _asper_.

There seems to be little adumbration of the dark marginal lines of _asper_ in populations from the lower Mississippi River drainage. Blackish spots and ocelli vary in size and there are many kinds of pattern on the carapace. Soft-shelled turtles inhabiting the Mississippi River and its tributaries in Louisiana and Mississippi certainly represent an intergrading population of _spinifer_ and _hartwegi_, and, to a lesser extent, of _asper_. Soft-shelled turtles inhabiting the Pearl River drainage and rivers that drain into Lake Pontchartrain immediately adjacent to the east are predominantly _asper_.

Specimens having localities from the Pearl River and Lake Pontchartrain drainages are listed under the account of _asper_ and are referred to that subspecies on the distribution map; specimens from the Mississippi drainage in Mississippi are referred to _spinifer_.

One specimen (UMMZ 59198, Bradley County, Tennessee), from the Tennessee River drainage where _T. s. spinifer_ occurs, deviates markedly from _spinifer_ and suggests intergradation. UMMZ 59198, plastral length 4.8 centimeters, has ocelli in the center of the carapace only two millimeters in diameter, a distinct but interrupted, second marginal ring consisting of spots, and the pale postlabial and postocular stripes in contact on both sides of the head.

_Specimens examined._--Total 110, as follows: ALABAMA: _Barbour_: UMMZ 113038, Chattahoochee River, Eufala. _Cherokee_: ANSP 24592, "near" center of Terrapin Creek. _Conecuh_: UMMZ 70736, Murder Creek, Castleberry. _Escambia_: TU 15823, Escambia River, 1 mi. N Sardine; UMMZ 70734, Escambia River at Flomaton. _Henry_: TU 15630, 3 mi. NW jct. Echo Farm Rd. and Rt. 136 on Echo Farm Rd. _Lowndes_: UMMZ 67759, Pintlalla Creek. _Mobile_: MCZ 1608 (2), 1608A, Mobile. _Sumpter_: USNM 83996, 3 mi. SE Coatopa. _Tuscaloosa_: TU 14673 (5), Black Warrior River, 17.5 mi. SSW Tuscaloosa; UA 52-1085, Cottondale. _Walker_: KU 50843, 50851, TU 17137, Mulberry Fork, Black Warrior River, 9 mi. E Jasper.

FLORIDA: _Calhoun_: KU 50837-38, Chipola River, 4 mi. N Scott's Ferry; TU 16689 (4), Chipola River "near" Blountstown. _Escambia_: TU 13474, 15869 (3), 16584, Escambia River, 1.2 mi. E Century. _Okaloosa_: TU 15661, Blackwater River, 4.3 mi. NW Baker on Route 4. _Santa Rosa_: AMNH 44621, Blackwater River, Milton. _Walton_: UMMZ 110421, Pond Creek, 4 mi. SW Florala, Covington County, Alabama.

GEORGIA: _Baker_: TU 15889 (3), USNM 134243-48, Flint River "near" Newton; USNM 30822. _Baldwin_: USNM 8708, Milledgeville. _Bryan_: TU 15090, Canouche River, 2.3 mi. W Groveland. _Chatham_: USNM 51981, 92583-84, Savannah. _Chattooga_: UMMZ 113037, tributary of Chattooga River, Lyerly. _Decatur_: KU 50839-42, Flint River, 1.5 mi. S Bainbridge. _Fulton_: UMMZ 53037, Roswell. _Lincoln_: USNM 91282-83, above Price Island, Savannah River. _Murray_: UMMZ 59196, 9 mi. N Spring Place. _Pulaski_: TU 14882, Ocmulgee River, 4.3 mi. SE Hawkinsville. _Richmond_: USNM 66859, Augusta. _Whitfield_: UMMZ 74209, Cohulla Creek, Prater's Mill "near" Dalton. _County unknown_: MCZ 37172; UMMZ 109864, Flint River at mouth of Dry Creek; USNM 029034.

LOUISIANA: _East Baton Rouge_: LSU 11, 1643-44, City Park Lake in Baton Rouge; TU 17237, Amite River "near" Baton Rouge. _St. Tammany_: TU 6356, headwater creek of Bayou Lacombe; TU 16071, USNM 66147, mouth of Tchefuncta Creek in Lake Pontchartrain. _Tangipahoa_: TU 13623, 3.1 mi. W Hammond; USNM 68054, Robert. _Washington_: KU 50840, 50846, TU 17117, Pearl River at Varnado. _Parish unknown_ (East Baton Rouge or Tangipahoa): UMMZ 95614, Manchac.

MISSISSIPPI: _Chickasaw_: USNM 115981, Chookatonkchie Creek. _Clarke_: USNM 79350-51, 1 mi. W Melvin, Choctaw County, Alabama; USNM 100805, Enterprise. _Forrest_: WEB 55-586, 1 mi. S Hattiesburg. _Hancock_: AMNH 46780; WEB 54-651, Hickory Creek "near" Kiln. _Lauderdale_: UMMZ 74681, 9 mi. W Meridian; UMMZ 90130, Lake Juanita, 15 mi. W Meridian. _Lawrence_: KU 47120, TU 17307.1, Pearl River, 9 mi. S Monticello; USNM 7653-54, Pearl River at Monticello. _Lee_: CM 31904, Verona; USNM 115979, Cower's Area near Guntown. _Madison_: USNM 95191, 95193-94, Pearl River. _Marion_: MCZ 1597, Pearl River at Columbus (designated type locality). _Pearl River_: CM 21100, Pearl River, 20 mi. W Poplarville; TU 14362, Hobolochito Creek, 1 mi. N Picayune. _Perry_: WEB 55-580, Beaver Dam Creek, 1 mi. N Richton. _Walthall_: KU 50844, Bogue Chitto River, Dillon.

SOUTH CAROLINA: _Abbeville_: USNM 7650, Abbeville? (reported by Pickens, 1927:113; locality considered in error by Stejneger, 1944:50; USNM 7650 having only one dark marginal line paralleling rear margin of carapace is possibly an aberrant specimen--see page 495 of present account). _Greenwood_: USNM 71681, 73668, Greenwood. _McCormick_: USNM 91310-12, Savannah River, 5 mi. W Plum Branch; USNM 92521, near Parksville. _Richland_: AMNH 70724-25, Broad River, Columbia.

NO DATA: USNM 8359 (erroneously reported from Madison, Indiana by Yarrow, 1882:29 and Hay, 1892:145; see discussion by Cahn, 1937:200, and Stejneger, 1944:73-75); USNM 131859.

_Records in the literature._--ALABAMA: _Coffee_: Elba (KKA). _Marengo_: Tombigbee River near Demopolis. _Mobile_: Fig Island (Löding, 1922:47).

FLORIDA: _Jackson_: Chattahoochee River, 8 mi. SE Butler. _Leon_: Ochlocknee River, NW of Tallahassee (Goin, 1948:304).

GEORGIA: _Bartow_: Etowah River below Allatoona Dam, _ca._ 4 mi. ESE Cartersville (Crenshaw and Hopkins, 1955:15). _Berrien_: (Knepton, 1956:324). _Emanuel_: Ogeeche River (Schwartz, 1956:19). _Fulton_: Nancy Creek, Atlanta (Dunston, 1960:278). _Gwinnett_: _Irwin_: (Knepton, _loc. cit._). _Jenkins_: Ogeeche River near Buckland Creek jct., 2.5 mi. S Millen. _Liberty_: Camp Stewart, 4 mi. N Hinesville. _Morgan_: Lake Rutledge (Schwartz, _loc. cit._). _Muscogee_: Columbus (Stejneger, 1944:52). _Wayne_: Altamaha River, 5 mi. N Mt. Pleasant (Schwartz, _loc. cit._). _Wilcox_: Ocmulgee River, 3-4 mi. SSE Abbeville (Crenshaw and Hopkins, _op cit._:16, footnote; Schwartz, _loc. cit._).

MISSISSIPPI: _George_: Whiskey Creek (Cook, 1946:185). _Harrison_: near Biloxi. _Jackson_: Pascagoula Swamp, _ca._ 40 mi. E. Biloxi (Corrington, 1927:101). _Jones_: Eastabuchie. _Lee_: Cain Creek Bottom. _Lincoln_: Old Brook Creek. _Lowndes_: Tombigbee River, Camp Henry Pratt and Columbus; Lake Park, Columbus. _Pearl River_: 21 mi. SW Poplarville; 10 mi. W Poplarville; 4 mi. W Poplarville. _Wayne_: Trigg Area (Cook, _loc. cit._).

NORTH CAROLINA: _Mecklenburg_: Catawba River near Charlotte (Schwartz, 1956:20).

SOUTH CAROLINA: _Aiken_: Savannah River, 10 mi. SW Jackson. _Allendale_: Savannah River, Fennell Hill, 2 mi. S US 301. _Anderson_: Pendleton. _Bamberg_: South Edisto River, Cannon's Bridge, 5 mi. from Bamberg. _Berkeley_: 2.5 mi. W Pinopolis. _Charleston_: Charleston. _Clarendon_: Upper Lake Marion at US 301; Lake Marion, 13 mi. SW Manning; 3.3 mi. S Jordan; 6.3 mi. S Jordan; Wyboo Creek, 8.5 mi. from Manning. _Colleton_: Edisto River (Schwartz, 1956:19-20). _Darlington_: Pee Dee River, Society Hill (Stejneger, 1944:72). _Dorchester_: Edisto River, 17 mi. from Summerville; Edisto River, 14 mi. W Summerville; Edisto River, 2.5 mi. S Hart's Bluff. _Fairfield_: 1 mi. N Peak, Newberry County. _Georgetown_: North Santee River, 1 mi. above US 17. _McCormick_: Little River near McCormick; Little River, 3 mi. NE Mt. Carmel. _Laurens_: Enoree River, 3 mi. S Cashville, Spartanburg County; Enoree River, 9.4 mi. N Clinton. _Orangeburg_: Edisto River, Orangeburg. _Saluda_: Batesburg; Lake Murray; Little Saluda River; 5 mi. from Saluda. _County unknown_: Upper Lake Santee (Schwartz, _loc. cit._).

=Trionyx spinifer emoryi= (Agassiz)

Texas Spiny Softshell

Plates 43, 44

_Aspidonectes emoryi_ Agassiz (in part), Contr. Nat. Hist. United
States, Vol. 1, Pt. 2, p. 407; Vol. 2, Pt. 3, pl. 6, figs. 4-5,
1857.

_T[rionyx] s[pinifer] emoryi_ Schwartz, Charleston Mus. Leaflet,
No. 26, p. 11, 1956.

_Type._--Lectotype, USNM 7855; alcoholic (sex undetermined); obtained from the Río Grande near Brownsville, Texas, in the course of the Mexican Boundary Survey under the command of Colonel Wm. H. Emory.

_Range._--Southwestern United States and northern México; the Río Grande drainage in Texas, New Mexico and northern México; the Río San Fernando and Río Purificación drainages in northeastern México; the Colorado River drainage in Arizona, New Mexico, and southern Nevada (see map, Fig. 19).

_Diagnosis._--Juvenal pattern of white dots, not encircled with dusky or blackish ocelli, confined to posterior third of carapace; pale rim of carapace conspicuously widened, four to five times wider posteriorly than laterally; a dark triangle in front of eyes, base line connecting anterior margins of orbits; pale postocular stripe interrupted leaving conspicuous pale, usually dark-bordered, blotch just behind eye.

_Description._--Plastral length of smallest hatchling, 2.5 centimeters (USNM 7632); of largest male, 13.0 centimeters (KU 2914, 3125, 3150); of largest female, 22.0 centimeters (TNHC 8023, 8104).

Carapace pale brownish or tan, lacking whitish dots on anterior half; whitish dots confined to posterior third of carapace, sometimes lacking posteriorly, especially on juveniles; small, blackish dots rarely occurring on surface of carapace, usually confined to margins when present; pale rim of carapace four to five times wider posteriorly than laterally.

Pattern on snout rarely variable, consisting of pale stripes extending forward from eyes that have only their outer borders darkened and a straight or slightly curved, dark line that connects anterior margins of orbits; few, if any, dark markings in subocular and postlabial region; pattern on side of head having few contrasting marks, often of nearly uniform coloration; postocular stripe usually interrupted; anterior segment of postocular stripe just behind eye usually dark-bordered; posterior segment usually not dark-bordered or sharply distinguished from background; pattern on dorsal parts of soft parts of body contrasting, of relatively small dark marks; dark streaks often coincident with digits.

Underparts whitish, occasionally having blackish dots or smudges on posterior part of carapace, in region of bridge, or on lateral parts of chin and throat; few dark marks often on webbing of limbs and on palms and soles.

Small, flattened or wartlike, tubercles that occasionally have sharp tips along anterior edge of carapace on adult males; tubercles flattened, scarcely elevated, never conical along anterior edge of carapace on large females; whitish, knoblike tubercles often present posteriorly in middle of carapace and in nuchal region on large females; mottled and blotched pattern sometimes contrasting on carapace of large females; whitish dots of juvenal pattern often visible through overlying blotched pattern of large females.

Ontogenetic variation in PL/HW, mean PL/HW of specimens having plastral lengths 7.0 centimeters or less, 3.68, and exceeding 7.0 centimeters, 5.19; ontogenetic variation in CL/CW, mean CL/CW of specimens having plastral lengths 8.5 centimeters or less, 1.17, and exceeding 8.5 centimeters, 1.27; mean CL/PCW, 2.18; mean HW/SL, 1.43; mean CL/PL, 1.37.

_Variation._--Ten topotypes (six males, three females, one juvenile) from Brownsville, Texas (BCB 7465-73, 7564), have the following characteristics: pale rim widened posteriorly as described above; females (plastral lengths 9.8, 10.2 and 11.7 cm.) having blackish marks in pale rim, which are absent in males of corresponding size; interrupted postocular stripe with pale blotch behind eye; postocular pale blotch having blackish borders or not; dark triangular mark on snout in front of eyes; white dots present only on posterior third of carapace; carapace of females grayish, blotched pattern not contrasting; carapace of males paler, greenish-gray; undersurface immaculate except 7468 and 7472 that have blackish flecks at bridge and, on 7472, blackish marks that extend posteriorly onto ventral surface of carapace; tubercles along anterior edge of carapace flattened and rounded in adult males, more knoblike in females; largest specimen, BCB 7472, female, plastron 11.7 centimeters long.

_T. s. emoryi_ varies more than any other subspecies of _Trionyx spinifer_. A large series of males and females (KU) from the Salt River (Colorado River drainage), near Phoenix, Arizona, is characterized by many adult males having indistinct white dots on posterior half of carapace; blotching on carapace of females of contrasting lichenlike figures, but usually non-contrasting and pale brownish or tan; pale rim of carapace distinct from ground color of carapace in largest female (KU 2905, plastron 21.5 cm. in length), but having dark or dusky markings: dark interorbital stripe often lacking. AMNH 58370 (Nevada) and UMMZ 92006 (Arizona) also have the dark line connecting the anterior margins of the orbits interrupted; seemingly the dark interorbital line is most often interrupted in those softshells inhabiting the Colorado River system of Nevada and Arizona.

Other variant individuals are: TU 14453.2, 14462 and 3696 having the plastron extending slightly farther forward than the carapace, thus resembling _T. ferox_; UMMZ 54021 and CNHM 39999, hatchlings, lacking distinct whitish dots on posterior half of carapace; UI 43509 and KU 39991 having stained (brown or blackish) claws; and, CNHM 6810, an adult male, lacking a spinose (sandpapery) carapace. I am unable to discern geographic variation in these or other characters.

The ground color of the carapace on some individuals from the Pecos River (TU, Terrell County, Texas) is grayish and in contrast with the pale rim (Pl. 44). UI 43509 from the Río Florida, La Cruz, Chihuahua, a female, has a dark brownish carapace with little evidence of a blotched pattern except on the pale rim of the carapace. A female and adult male from the Río Sabinas, Coahuila (MSU 905-06), also show considerable darkening on the dorsal surfaces; the pale rim is evident but not in sharp contrast to the coloration of the carapace. Notes taken on the freshly-killed Sabinas individuals are: male--carapace olive-gray; dorsal surface of soft parts of body olive-green to grayish, a bright yellow suffusion on limbs and neck; female--carapace and soft parts of body dark olive, laterally pale yellow; the plastron extends slightly farther forward than the carapace in both sexes.

Notes on coloration (judged to be the most common or "normal" type) of living _emoryi_ from the Río Mesquites, central Coahuila, are: Adult male (KU 53753)--pale rim butterscotch yellow; marginal line blackish; whitish dots on pale brown or tan carapace; soft parts of body olive or olive-green, slightly darker on head and paler (yellowish) on hind limbs; pale areas on side of head pale yellow, having tint of orange on neck; ventral surface white, yellow laterally on neck. Adult female (KU 53754)--carapace having contrasting blotched and mottled pattern of pale browns and tans; soft parts of body olive brown, darker brown blotching on head; dorsal surface of limbs olive-green having pale areas lemon yellow and webbing butterscotch yellow; side of neck and head, chin and throat pale lemon yellow; ventral surface white having slight red tinge to groin and soft parts posteriorly; underside of carapace near edge pale yellow.

Softshells from the Río Grande in the Big Bend region of Texas, and the Río Conchos in Chihuahua differ from other specimens of _emoryi_. Fifteen adult males, KU 51187-201 (no females in sample), were taken from the mouth of the Río San Pedro at Meoquí, Chihuahua (see KU 51194, Pl. 44). They are noteworthy because of a conspicuous orange or orange-yellow on the side of the head. Another relatively consistent character is the blackish tip of snout (excepting 51199), although the degree (palest on 51190) and extent of pigmentation posteriorly on the snout is variable. Eleven males, KU 51175-85, from approximately 100 miles northeastward in the Río Conchos near Ojinaga, Chihuahua, also have the bright orange on the side of the head; the tip of the snout is not blackish, although in some it is slightly darkened. Three females, KU 51174, 51186 (from Ojinaga) and 51173 (from 8 mi. S, 16 mi. W Ojinaga), lack the orange on the side of the head; KU 51186 has a plastral length of 8.0 centimeters, whereas the other two females have the same plastral length of 16.5 centimeters (larger than any male). Nineteen adult males, KU 51965-72, 51980-90, from the Río Grande near Lajitas also have the orangish coloration on the side of the head, whereas twenty females, KU 51954-64, 51973-79, 51991-92 (three smaller than largest male) lack the coloration. The tip of the snout is not blackish on any turtle in the series from Lajitas. The smallest female, from Lajitas, having a plastral length of 6.9 centimeters, has a mottled carapace.

The orange of males is most conspicuous in the pale postocular and postlabial areas; the stripes of the snout (distally) and the color of the neck at its juncture with the immaculate ventral surface are orange-yellow. The orange coloration is confined to males (all examined were sexually mature) and is probably not of seasonal occurrence (see comments under secondary sexual variation). I have not noticed this coloration in other males of the subspecies _emoryi_; however, long-preserved males might be expected to lack the orange color; the specimens mentioned above were initially preserved in alcohol. KU 51179 (plastral length 8.2 cm., from Ojinaga) is the smallest sexually mature male of the species _spinifer_ that I have seen. Another character of note is the generally greater development of the plastral callosities (resembling _muticus_) than in other subspecies of _spinifer_ or specimens of _emoryi_; three small adult males (KU 51177, 51990, 51987, plastral length 9.3, 9.9 and 9.1 cm., respectively) have large hyoplastral and hypoplastral callosities that appear to touch medially, and callosities on the epiplastron and both preplastra.

On July 8, 1953, an adult male of _T. spinifer_ was removed from a hoop-net set in the Río Purificación at Padilla, Tamaulipas, México. I was particularly impressed by the lack of whitish dots on the dark carapace; the following notes were taken from the freshly-killed specimen: carapace a uniform dark olive, lacking white dots and having a yellowish rim widest posteriorly; tubercles on anterior edge of carapace only slightly raised, inconspicuous; top of head olive with few dots and streaks; a well-defined yellowish postocular stripe not conspicuously interrupted; sharp contrast between dark olive on side of head and pale ventral coloration; yellowish-orange ventrolaterally on head; an uninterrupted slightly-curved line connecting the anterior margins of the orbits; carapace pear-shaped; underparts whitish, lacking markings. This specimen has since been destroyed. The only other specimen I have seen from this locality is a hatchling (UMMZ 69412, Pl. 43), which has a pale brownish or tan carapace that lacks whitish dots; it resembles _emoryi_ in other characters. Although the absence of whitish dots is not distinctive, its combination with the uniform dark olive carapace in adult males and the fact that the Río Purificación is an isolated drainage system, suggests that soft-shelled turtles from that river system may warrant further taxonomic study.

_Comparisons._--From all other subspecies of _spinifer_, _T. s. emoryi_ can be distinguished by having a pale rim on the carapace that is four to five times wider posteriorly than it is laterally. This character, unique for _emoryi_, combined with patterns on the snout, side of head and carapace that are subject to little variation, permit ready identification of the subspecies _emoryi_. _T. s. emoryi_ resembles _pallidus_, and _guadalupensis_ and differs from _spinifer_, _hartwegi_ and _asper_ in having whitish tubercles or dots on the carapace. _T. s. emoryi_ resembles _guadalupensis_ but differs from _pallidus_, _spinifer_, _hartwegi_ and _asper_ in lacking conical tubercles along the anterior edge of the carapace on large females. For additional differences see accounts of other subspecies.

Some populations of _T. s. emoryi_ resemble _T. muticus_ in the size at which sexual maturity is attained and in the development of the plastral callosities. _T. s. emoryi_ has a wide head that resembles that of _T. ferox_, _T. ater_, _T. s. asper_ and _T. s. guadalupensis_; _T. s. emoryi_ also resembles _T. ferox_ and _T. ater_ but differs from the other subspecies of _T. spinifer_ and _T. muticus_ in having a narrower carapace. _T. s. emoryi_ resembles _T. s. guadalupensis_, _T. s. pallidus_ and _T. ater_, and differs from the other subspecies of _spinifer_ and _T. muticus_, in having the carapace widest farther posteriorly than one-half way back on the carapace. _T. s. emoryi_ resembles _T. ferox_ in having the shortest length of snout of the subspecies of _spinifer_. The plastron is shorter than in _T. ferox_, longer than in _T. s. asper_, and about the same length as in _T. muticus_ and the other subspecies of _T. spinifer_.

_Remarks._--Agassiz (1857, 1:407-08) did not designate a holotype in the original description of _Aspidonectes emoryi_; specimens are mentioned from the lower Río Grande of Texas, near Brownsville, and a stream of the Río Brazos drainage in Williamson County, Texas. The description is applicable to _T. s. emoryi_ as herein restricted, except for the statement that the white tubercles of young specimens are "encircled by faint black lines"; that statement is presumably based on the juveniles from Williamson County. _T. s. emoryi_ does not occur in Williamson County, Texas. Barbour and Loveridge (1929:225) listed MCZ 1909-10 and 1627 as cotypes. Stejneger (1944:65) mentioned MCZ 1909, 1913 and USNM 7855 as cotypes; the legend for Plate 20 (_op. cit._) refers to a drawing that "corresponds fairly closely with the type (MCZ 1910) collected at Brownsville, Texas, by Col. Emory."

The syntypic series consists of seven specimens--MCZ 1627 (two specimens) from Williamson County, Texas; MCZ 1909 (three specimens) and 1910 from Brownsville, Texas; and USNM 7855 from Brownsville, Texas. The listing of number 1913 by Stejneger is considered a _lapsus_ for 1910 as MCZ 1913 is catalogued as a _Graptemys geographica_ (in letter dated November 17, 1959 from Dr. Ernest E. Williams). Stejneger's reference to MCZ 1910 as the type is considered unintentional and an inadequate designation of a lectotype.

In the "remarks" column of the USNM museum catalog, number 7855 is referred to as "Ag. Type." USNM 7855 is here designated as lectotype of _Trionyx spinifer emoryi_. The lectotype is a young specimen (female?) that is not easily sexed by external characters; the plastron measures (in centimeters) 6.3 in length, the carapace 8.2 in length and 7.0 in width, and the head 1.4 in width. The carapace is pale brown having inconspicuous whitish dots posteriorly and a pale rim that is approximately 6.8 times wider posteriorly (4.1 mm.) than it is laterally (0.6 mm.). The slightly curved dark line connecting the anterior margins of the orbits is dimmer than the dark lines that extend forward from the eyes. The pale postocular stripes having blackish, dotted borders are interrupted; there are no other markings on the side of the head. The ventral surface is immaculate except for a few dark dots on the right side of the carapace; the ground color is pale brown or tan, but the upper layer of skin can be scraped away revealing an underlying pale lavender-cream ground color. The tubercles along the anterior edge of the carapace resemble small rounded warts.

MCZ 1910 is an adult male _T. s. emoryi_ having a plastron 10.7 centimeters in length. The carapace is pale brown having a relatively smooth anterior edge, inconspicuous whitish tubercles posteriorly, and a pale rim five times wider posteriorly than laterally; the pattern on the head resembles that of _emoryi_.

Each of three hatchlings of _T. s. emoryi_, 3.4, 3.5 and 3.9 centimeters in plastral length, bears an MCZ catalogue number of 1909. The carapaces are dark tan or gray having pale rims 3.7, 5.2 and 5.2 times wider posteriorly than laterally, and white dots absent or obscure posteriorly; two specimens have small blackish dots paralleling the pale rim posteriorly. The patterns on the heads are referable to _emoryi_.

The two juvenal syntypes (5.2 and 6.1 cm. in plastral length) from Williamson County, Texas, are both catalogued as MCZ 1627, but only one of these bears a catalogue number. The two softshells are not _emoryi_, and are more nearly like _T. s. guadalupensis_ than _T. s. pallidus_. Actually, they are from an area of intergradation between those subspecies (see comments concerning intergradation under the accounts of the subspecies _pallidus_ and _guadalupensis_). White spots occur on the carapaces anteriorly and posteriorly, the larger (more posterior) of which are encircled with dusky ocelli. The carapace of the small specimen (bearing no number) is brown having a few, small black specks intermixed with the white spots. The carapace of the large specimen is pale lavender and has a more obscure pattern than the other specimen.

After Agassiz's description, _emoryi_ was accepted as a distinct species. Neill (1951:15) suggested that _emoryi_ was subspecifically related to _T. ferox_. Crenshaw and Hopkins (1955) and Schwartz (1956), however, demonstrated that _ferox_ was a distinct species; _emoryi_ has since been considered a subspecies of _T. spinifer_.

Two specimens having blackish dots on the carapace, indicate relationship with _T. s. guadalupensis_. USNM 7638, a hatchling, has large whitish dots surrounded by blackish dots confined to the posterior half of the carapace, and the locality for this specimen is merely Río Bravo (= Río Grande). CNHM 47366, a hatchling from Sierra de las Palmas (Sierra de Santa Rosa, La Palma), Coahuila, has a few, small, blackish dots, irregularly spaced, on the anterior half of the carapace, but other dots more evenly distributed on the posterior half where they are intermixed with whitish dots. The drawing of the dorsal view of a hatchling _emoryi_ (Agassiz, 1857:Pl. 6, Fig. 4) shows a sprinkling of blackish dots on the anterior half of the carapace. A hatchling from Eagle Pass (USNM 116578) does not have a noticeably widened pale rim posteriorly on the carapace, and is not distinguishable from _pallidus_. See account of _T. s. guadalupensis_ for further comments on intergradation.

A soft-shelled turtle that was obtained in the Sacramento River by three fishermen, near Sacramento, California, was named _Aspidonectes californiana_ by Rivers (1889:233). A comparison (with _Aspidonectes spinifer_ and _A. emoryi_) of certain features of the skull was largely prepared by Baur and included in the description (_op. cit._:234-35); seemingly, the most trenchant character of the skull of _californiana_ was the enlarged alveolar surfaces of the jaws. This feature prompted Baur (1893:220) to refer _californiana_ to the genus _Pelodiscus_, which also included _agassizi_ (skulls also having jaws with enlarged alveolar surfaces) and several Old World species. Van Denburgh (1917) discussed the origin of the specimen that formed the basis of River's description and concluded that it was brought over from China. Siebenrock (1924:192) and Mertens and Wermuth (1955:389) listed _Aspidonectes californiana_ as a synonym of _emoryi_. River's description is not that of _emoryi_; the enlarged alveolar surfaces of the jaws, and the dark carapace having tubercular ridges suggest a resemblance to _T. ferox_. The papillae on the neck are not found in any American species. Miller (1946:46, footnote 2) believed that "it obviously was introduced, apparently from China," and cited Pope (1935:61), who declared the specimen to represent _Trionyx sinensis_.

Schmidt (1924:64) first reported the occurrence of _T. s. emoryi_ west of the continental divide in Arizona and suggested that it was highly probable that the species had been introduced near Phoenix in recent years. Cowles and Bogert (1936:42) mentioned a species of softshell occurring in the Boulder Dam region and presumed the species to be native to Asia and introduced by the Chinese. Linsdale and Gressitt (1937:222) determined the status of the species in the Colorado River drainage as _T. s. emoryi_. The discussions by Dill (1944:179-81) and Miller (1946:46) indicate that _emoryi_ was introduced into the Gila River (Colorado River drainage) in western New Mexico near the turn of the century.

_T. s. emoryi_ and _T. ater_ are the only kinds of softshells occurring in México. The colloquial name for soft-shelled turtles in México is "tortuga blanca." This name is also used in reference to the Central American river turtle, _Dermatemys mawei_, which occurs on the east coast of México as far north as Veracruz.

_Specimens examined._--Total 275, as follows: ARIZONA: _Maricopa_: CNHM 4768, KU 2214-19, 2803, 2824, 2837, 2903-07, 2909-16 (2914, 2 specimens), 2918-29, 3118-27, 3129, 3147-56, USNM 71627, Salt River, Phoenix. _Pinal_: UI 37713, Gila River, 6 mi. E Winkleman; UMMZ 92006-07, Gila River, 1/2 mi. below Coolidge Dam; UMMZ 105824, San Pedro River about 1 mi. above confluence with Gila River.

NEVADA: _Clark_: AMNH 58370, Boulder City boat landing, Lake Mead; TU 15802, Virgin River, Mesquite.

NEW MEXICO: _Eddy_: KU 15938, Carlsbad; KU 48217-18, Black River Village. _Grant_: AMNH 79911, Gila River, 8 mi. NE Cliff.

TEXAS: _Brewster_: CNHM 39999, Tornillo Creek near jct. with Río Grande; KU 51954-92, Lajitas; TCWC 4291, UMMZ 66471, USNM 45545, 103678, Boquillas; INHS 7975, UMMZ 114360, Hot Springs. _Cameron_: BCB 7564-73, CNHM 5339-40, 6810, MCZ 1909 (3), 1910, TU 11479-80, 11561-62, UMMZ 54021, 105209-13 (Brownsville Lake), USNM 7642, 7644, 7855, Brownsville; BCB 5121, 3 mi. S Harlington. _El Paso_: UMMZ 85085, El Paso; USNM 7641, 7701, El Paso del Norte. _Hudspeth_: USNM 20846, Fort Hancock on Río Grande. _Kinney_: CNHM 26090, Río Pinto W of Bracketville; USNM 26426-36, Fort Clark. _Loving_: TTC 1143, Red Bluff Lake just below dam on Pecos River. _Maverick_: TU 3696-97, UMMZ 116578, Eagle Pass. _Presidio_: TTC 628 (2), 632 (2), 3 mi. WNW Lajitas, Brewster County. _Terrell_: TNHC 7997, 8022-23, Chandler Ranch, 30 mi. S Sheffield, Pecos County; TNHC 8104, Dunlap Ranch, 25 mi. SE Sheffield, Pecos County; TU 14453 (7), 14462 (2), 15415, 15423, 15586, Pecos River near jct. with Independence Creek; USNM 104240, Pecos River "near" Dryden. _Val Verde_: TTC 113, Pecos River. _Webb_: TNHC 19788, 42 mi. NW Laredo; USNM 109078-79, Laredo. _Zapata_: UI 19332, "near" Zapata. _County unknown_: MCZ 1628, USNM 7635-36, 7854; USNM 7637-38, Río Bravo (= Río Grande).

CHIHUAHUA: KU 51173, 8 mi. S, 16 mi. W Ojinaga; KU 51174-86, 1 mi. NW Ojinaga; KU 51187-201, Río Conchos at mouth of Río San Pedro near Meoquí; UI 43508-09, Río Florida, La Cruz.

COAHUILA: CNHM 26054, Sta. Helena Canyon of Río Grande; CNHM 28846, "near" Músquis; CNHM 55657, Río Alamos, Rcho. de la Gacha; CNHM 47366, Sierra de Santa Rosa, La Palma; CNHM 47367, 55661, Cuatro Ciénegas; CNHM 55658-60, Rcho. de los Borregos near Juarez; KU 33523, La Presa Don Martín; KU 39991, 39993, 8 mi. N, 2 mi. W Piedras Negras; KU 39992, 2 mi. W Jiménez; KU 46907, 16 km. S Cuatro Ciénegas; KU 46913-16, 10 km. S Cuatro Ciénegas; KU 53752-54, Río Mesquites, 8 mi. W Nadadores; KU 53757, 8.5 mi. SW Cuatro Ciénegas; MSU 905-06, Río Sabinas, 1 mi. E Sabinas.

NUEVO LEON: CNHM 1874, 2191, Rodriguez; UMMZ 69411, Río Conchos, 9 mi. N Linares.

TAMAULIPAS: CM 3037, Nuevo Laredo. UMMZ 7614-20, 7622-25, 7628, 7630, 7632-33, Matamoros; UMMZ 69412, Río Purificación, N of Ciudad Victoria.

NO DATA: MCZ 1629 (2), NHB 1032.

_Records in the literature._--ARIZONA: _Greenlee_: Gila River, Duncan (Miller, 1946:46); "near" Sheldon (Dill, 1944:180). _Mohave_: Pierce's Ferry just below lower end of Grand Canyon (Cowles and Bogert, 1936:42); 1.5 mi. upstream (Virgin River) from Mesquite, Clarke County, Nevada (Hardy and Lamoreaux, 1945:168); Lake Havasu on Colorado River (Dill, 1944:180). _Yuma_: Colorado River at Headgate Rock Dam (Dill, _op. cit._:179).

CALIFORNIA: _Imperial_: California Lakes (Cowles and Bogert, 1936:42); Palo Verde; Colorado River at Laguna Dam (Dill, 1944:180).

NEVADA: _Clark_: observed just north of Black Canyon (Cowles and Bogert, _loc. cit._); Colorado River, 6 mi. N California line (Linsdale, 1940:255).

NEW MEXICO: _Chaves_: Bitter Lakes Wildlife Refuge, 12 mi. NE Roswell (Bundy, 1951:314). _Dona Ana_: Río Grande near Mesilla Dam (Little and Keller, 1937:221).

TEXAS: _Brewster_: Río Grande at Castolon (Minton, 1959:38). _Val Verde_: mouth of Devil's River (Brown, 1950:250).