Chapter II: Part 2

Taylor (1943a:347) described _Bufo perplexus_ from Mexcala on the Rio Balsas in Guerrero. Among the many paratypes are specimens from Tonola, Chiapas, and Tehuantepec, Oaxaca. These apparently were referred to _perplexus_ solely on the nature of the cranial crests. All of the specimens examined during the course of the present study from the lowlands of Veracruz and from the Pacific lowlands from Sinaloa southward to Chiapas are referable to _Bufo marmoreus_; those from the Balsas-Tepalcatepec Basin are referable to _Bufo perplexus_, as defined above. Ten specimens from Chilpancingo, Guerrero (UMMZ 115352), do not readily fit either species. Perhaps there is gene exchange between the inland and coastal populations through the relatively low pass at Chilpancingo, at the mouth of the Rio Balsas, and near the convergent headwaters of the Rio Coahuayana and Rio Tepalcatepec in southern Jalisco. If this can be demonstrated, then _Bufo perplexus_ would have to be considered as a subspecies of _Bufo marmoreus_, instead of an allopatric species.

~Bufo perplexus~ Taylor

_Bufo perplexus_ Taylor, Univ. Kansas Sci. Bull., 29:347,
October 15, 1943.--Balsas River near Mexcala, Guerrero,
Mexico.

Aguililla (2); Apatzingan (42); Buena Vista (5); Capirio
(3); La Playa (25); Lombardia (6); Nueva Italia (9); Rio
Cancita, 14 km. E of Apatzingan; Rio Tepalcatepec, 27 km. S
of Apatzingan; San Salvador (4); Tzitzio; Volcan Jorullo.

~Bufo occidentalis~ Camerano

_Bufo occidentalis_ Camerano, Atti R. Accad. Sci. Torino,
14:887, December 31, 1878.--Mexico. Type locality restricted
to Guanajuato, Guanajuato, Mexico, by Smith and Taylor
(1950a:330). Firschein, Copeia, no. 3:220, September 15,
1950.

_Bufo simus_, Smith and Taylor, Bull. U. S. Natl. Mus.,
194:42, 1948.

Barranca Seca (32); Cerro de Barolosa (4); Cerro Tancitaro,
3 km. E of Apo (2); Cerro Tancitaro, 19 km. E. of Apo (10);
Charapendo; Coalcoman (7); Dos Aguas (4); Jacona, Jaramillo
(2); Las Tecatas; Los Reyes (181); Tancitaro (10); Uruapan
(3).

This toad is an inhabitant of pine and oak forests between 900 and 2400 meters. Near Charapendo on the slopes of the Sierra de los Tarascos and at Coalcoman it apparently reaches its lowest altitudinal limits. At both of these localities the pine-oak forest is replaced by arid tropical scrub forest on the lower slopes.

Twenty-four tadpoles were collected on May 3 in a quiet section of a fast stream near Barranca Seca. The tadpoles have a robust body, broadest about two-thirds the distance from the snout to the posterior edge of the body, half again as broad as deep. Eyes dorsolateral; nostrils dorsal, somewhat directed forward, and about three-fifths the distance from the tip of the snout to the eye; spiracle sinistral and lateral, located at about midbody; anus median; tail long and slender; tail-musculature extends nearly to tip of tail; depth of tail-musculature at mid-length about one-third total depth of tail; dorsal tail-fin not extending onto body (Fig. 5); average body length of ten tadpoles having small hind limb buds, 14.4 mm.; average tail length, 22.0 mm.

Mouth ventral, nearly terminal, about one-third as wide as widest part of body; anterior lip has no papillae; lower lip bordered by two rows of papillae and lateral lips by one row of papillae; beaks moderately well developed, the upper forming a broad arch and finely denticulate; tooth rows 2/3, the upper rows extending to the edge of the lips, subequal in length, and slightly longer than lower rows, which also are subequal in length; inner upper tooth row broken medially; inner lower tooth row sometimes broken (Fig. 6).

The body is black dorsally and laterally, and bluish gray ventrally; the tail musculature is brown and stippled with darker brown. The fins are transparent and stippled with brown, the stippling being most pronounced on the posterior two-thirds of the upper tail-fin.

Forty recently metamorphosed individuals average 18.9 mm. in snout-vent length.

The relationships of this toad seem to be with _Bufo bocourti_ Brocchi, an inhabitant of pine and oak forests in the uplands of Chiapas and Guatemala. In _Bufo occidentalis_ the tympanum usually is indistinct and sometimes completely covered, and it is absent in _bocourti_. _Bufo occidentalis_ has a broader interorbital area and relatively shorter and more rounded parotid glands than _bocourti_. The tadpoles of the two species are nearly identical (see Stuart, 1943:12).

~Leptodactylus labialis~ (Cope)

_Cystignathus labialis_ Cope, Proc. Amer. Philos. Soc.,
17:90, 1877.--No type locality designated; type locality
restricted to Potrero Viejo, Veracruz, Mexico, by Smith and
Taylor (1950a:350).

_Leptodactylus labialis_, Brocchi, Mission Scientifique au
Mexique et dans l'Amerique Centrale, pt. 3, sec. 2, livr.
1:20, 1881.

Apatzingan (26); Capirio (5); Cofradia (9); El Sabino (4);
Lombardia; Rio Tepalcatepec, 27 km. S of Apatzingan (2).

In the Tepalcatepec Valley this frog reaches the northernmost known limit of its range in western Mexico. Although the species is abundant in the valley, it apparently is absent from the coastal lowlands. In the Tepalcatepec Valley _Leptodactylus melanonotus_ seems to be more abundant than _labialis_. In the rainy season both species have been heard calling from the same ponds and flooded fields.

There are only slight differences in size between the sexes; measurements of 20 males and eight females are, respectively: snout-vent length, 32.3-39.5 (35.1), 34.1-39.2 (37.2); tibia length, 14.3-17.0 (15.4), 14.9-16.8 (15.8); head width, 11.0-13.6 (12.0), 12.2-13.2 (12.6); head length, 12.8-15.1 (13.3), 12.8-14.6 (13.7).

~Leptodactylus melanonotus~ (Hallowell)

_Cystignathus melanonotus_ Hallowell, Proc. Acad. Nat. Sci.
Philadelphia, 12:485, 1861.--Nicaragua. Type locality
restricted to Recero, Nicaragua, by Smith and Taylor
(1950a:320).

_Leptodactylus melanonotus_, Brocchi, Mission Scientifique
au Mexique et dans l'Amerique Centrale, pt. 3, sec. 2, livr.
1:20, 1881.

Apatzingan (103); Capirio; Charapendo (7); Coahuayana;
Cofradia (10); El Sabino (21); La Playa (3); Lombardia (5);
Maruata; Nueva Italia (7); Ostula (9); Playa Azul (11); Rio
Marquez, 10 km. S of Lombardia; Rio Marquez, 13 km. SE of
Nueva Italia (6); Rio Tepalcatepec, 27 km. S of Apatzingan.

This species is widespread in the lowlands of the state; it has been collected up to elevations of 1050 meters in the Tepalcatepec Valley. In the dry season individuals were discovered beneath rocks along streams and in damp arroyos; in the rainy season they were found wherever there was water. Males were heard calling from flooded fields, ditches, rocky streams, and small puddles. The call is a series of individual notes: "woink, woink, woink."

Adult males are noticeably smaller than females; measurements for 20 males and ten females from Apatzingan are, respectively: snout-vent length, 29.6-34.6 (32.3), 36.3-44.1 (40.8); tibia length, 12.6-15.1 (14.0), 16.5-19.0 (17.8); head width, 10.8-11.9 (11.3), 12.6-14.8 (13.7); head length, 11.2-13.2 (11.9), 13.1-14.8 (14.0). Brownish yellow ventral glands are present in some juveniles and in some adults collected in the dry season as well as in the rainy season.

~Leptodactylus occidentalis~ Taylor

_Leptodactylus occidentalis_ Taylor, Trans. Kansas Acad.
Sci., 39:349, 1937.--Tepic, Nayarit, Mexico.

Five km. W of Tangamandapio.

On the night of June 11, 1958, this species was calling from a hyacinth-choked ditch. Although numerous individuals were heard, only one specimen was obtained. The frogs were calling from the tangled mat of hyacinths along with _Hyla eximia_, _Hypopachus oxyrrhinus ovis_, and _Rana pipiens_.

Taylor (1936a:352) characterized this species as follows: "The narrow head, small maximum size (38 mm. for females, 33 mm. for males), the character of the postaxillary and postfemoral glands, the narrower groups of vomerine teeth, clearly distinguish this western Mexican form from the more robust, larger _melanonotus_ to the south. The call is likewise fainter and different in quality." Concerning the glands, Taylor (_loc. cit._) remarked: "There is a possibility that the horny excrescence covering the glands may appear only during the breeding season. This character is quite as strongly marked in females as in males." Bogert and Oliver (1945:324) concluded that the population of _Leptodactylus_ in northwestern Mexico could not be distinguished from _melanonotus_ in other parts of the country and thus synonymized _Leptodactylus occidentalis_ with _melanonotus_. Bogert and Oliver (op. cit.: 324) stated that the extent as well as the presence or absence of ventral glands was highly variable in all samples examined by them.

Upon seeing numerous living individuals of _Leptodactylus melanonotus_ from many parts of its range in Mexico and individuals of the population of _Leptodactylus_ in northwestern Mexico (Nayarit and Sinaloa), I was immediately impressed not so much by the differences in the development of the ventral glands, but by the color of the glands. The differences in color are apparent in freshly preserved specimens. With the exception of _Leptodactylus_ from northwestern Mexico, specimens of _melanonotus_ from throughout Mexico and northern Central America have yellow or yellowish brown glands. Specimens from northwestern Mexico have black or brownish black glands that are conspicuously darker than those found in _melanonotus_. Examination of 653 preserved specimens of _Leptodactylus melanonotus_ from Mexico and Guatemala has failed to reveal specimens with black ventral glands, like those found in specimens from northwestern Mexico, to which the name _Leptodactylus occidentalis_ has been applied. Furthermore, in _melanonotus_ the glands are less distinct and more extensive than in _occidentalis_; in the latter species glands are absent from the throat and midventral area, where they often are present in _melanonotus_ (Fig. 7).

In some individuals of both species collected in the dry season and in some collected in the rainy (breeding) season the glands are absent; the development of these glands, therefore, does not seem to be correlated with breeding. Likewise, the glands are present or absent in either sex, and often as not they are present in juveniles. Presence of the glands, therefore, cannot be correlated either with sexual or ontogenetic development. Since the glands are found in individuals from all parts of the range, it is unlikely that there is a correlation between the development of the glands and the environment.

Aside from the differences in the ventral glands, the call is different in the two populations. The call of _Leptodactylus occidentalis_ is a rather harsh "wack, wack, wack" as contrasted with the more nasal "woink, woink, woink" of _melanonotus_. Sound spectrographs are needed to analyze the differences in calls. None of the specimens of _occidentalis_ examined approaches in size the largest individuals of _melanonotus_; possibly the size of the frogs is another valid character for separating the species. On the basis of the above data it is evident that the frogs in northwestern Mexico show certain characters that distinguish them from _Leptodactylus melanonotus_, as it is known throughout the rest of Mexico. It is not known for certain that _melanonotus_ and _occidentalis_ are sympatric. Several series of old, poorly preserved specimens from Nayarit and Sinaloa cannot be placed in either species, for none has visible ventral glands. _Leptodactylus melanonotus_ is known from Acaponeta, Nayarit (AMNH 43913-25), and the following localities in Jalisco: Barro de Navidad (UMMZ 118098), La Concepcion (UMMZ 113081), La Resolana (UMMZ 102104), and Tenachitlan (UMMZ 113045-6). Records for _Leptodactylus occidentalis_ are: Alamos, Sonora (AMNH 51356-65); Culiacan (AMNH 49511-9), Chele (UMMZ 110914), and Rosario (UMMZ 113062) in Sinaloa; Ixtlan del Rio (UMMZ 102108), San Blas (UMMZ 112814, 112994, 110892, 115543), and Tepic (UMMZ 115544) in Nayarit; Ameca (UMMZ 102106-7) and La Cofradia on the south shore of Lago de Chapala (UMMZ 102105) in Jalisco; and Tangamandapio, Michoacan (UMMZ 119145). From these scattered records it appears that _Leptodactylus occidentalis_ in the southern part of its range stays in the uplands, whereas _melanonotus_ is confined to the lowlands.

~Microbatrachylus hobartsmithi~ (Taylor)

_Eleutherodactylus hobartsmithi_ Taylor, Trans. Kansas Acad.
Sci., 39:355, 1937.--Uruapan, Michoacan, Mexico.

_Microbatrachylus hobartsmithi_ Taylor, Univ. Kansas Sci.
Bull., 26:501, November 27, 1940.

Cascada Tzararacua (6); 21 km. W of Ciudad Hidalgo; 29 km. E
of Morelia; Puerto Hondo; San Jose de la Cumbre (13);
Uruapan (2); Zitacuaro.

Of six specimens from Cascada Tzararacua, five are colored like typical _M. hobartsmithi_, having the anterior and posterior surfaces of the thighs and the upper arms pale pink in life and a grayish brown dorsum in preservative. The other specimen (UMMZ 94231) has in preservative a dark brown dorsolateral line on each side enclosing a pale tan area that extends from the snout to the vent. One specimen from 29 kilometers east of Morelia (UIMNH 40338) and 13 specimens from San Jose de la Cumbre (UMMZ 102111) do not have the prominent tarsal tubercles characteristic of _M. hobartsmithi_. Also, in these fourteen specimens the palmar tubercles are larger, and the dark anal patch more distinct, than in typical _M. hobartsmithi_. Possibly these specimens, which are from the high mountains in the eastern part of Michoacan, represent another species of _Microbatrachylus_. However, Taylor (1940d:501) reported a series of _M. hobartsmithi_ from the mountains 10 miles west of Villa Victoria in the western part of the state of Mexico.

The largest specimen from Michoacan is a gravid female (UIMNH 16104) having a snout-vent length of 23.5 mm.

_Microbatrachylus hobartsmithi_ has been found in rocky ravines along streams in the Cordillera Volcanica and the southwestern escarpment of these mountains at elevations from 1450 to 2750 meters.

~Microbatrachylus pygmaeus~ (Taylor)

_Eleutherodactylus pygmaeus_ Taylor, Trans. Kansas Acad.
Sci., 39:352, 1937.--1 mile north of Rodriguez Clara,
Veracruz, Mexico.

_Microbatrachylus pygmaeus_ Taylor, Univ. Kansas Sci. Bull.,
26:500, November 27, 1940.

_Microbatrachylus albolabris_ Taylor, Univ. Kansas Sci.
Bull., 26:502, November 27, 1940.--2 miles west of Cordoba,
Veracruz, Mexico.

_Microbatrachylus minimus_ Taylor, Univ. Kansas Sci. Bull.,
26:507, November 27, 1940.--Agua del Obispo, Guerrero,
Mexico.

_Microbatrachylus imitator_ Taylor, Univ. Kansas Sci. Bull.,
28:70, May 15, 1942.--La Esperanza, Chiapas, Mexico.

Arteaga (328).

This large series (UMMZ 119247-8) was collected on June 22 and 23, 1958, before the onset of the heavy summer rains. The frogs were found in a shaded ravine at the north edge of Arteaga; they were obtained during the day, at which time they were actively moving about in the leaf litter along a small stream.

These frogs are all referred to _M. pygmaeus_, because this is the earliest name available for frogs showing the variation in characteristics displayed by this large series. The characters used by Taylor (1936a, 1940d, 1941a, and 1942b) and Smith and Taylor (1948) to distinguish the various species of _Microbatrachylus_ include color pattern, relative length of the hind limb, presence and position of dorsal dermal folds or pustules, relative size of inner and outer metatarsal tubercles, and the number of palmar tubercles. All specimens from Arteaga have two palmar tubercles; the inner and outer metatarsal tubercles are subequal in size. Furthermore, aside from sexual difference, there is little variation in the relative length of the hind limbs (Table 3). However, many color patterns do exist in the series; each of these color patterns is described below.

TABLE 3.--SNOUT-VENT LENGTH EXPRESSED AS A PERCENTAGE OF TIBIA LENGTH IN ANIMALS OF SIX COLOR PATTERNS OF MICROBATRACHYLUS PYGMAEUS. (LETTERS REFER TO THE VARIANTS HAVING THE COLOR PATTERN DISCUSSED IMMEDIATELY BELOW)

+------------+-----------+---------+---------+----+--------+ | | | Number | Range | | Twice | | Color | Sex | of | of |Mean|standard| |Pattern | |specimens|variation| | error | | | | | | |of mean | +------------+-----------+---------+---------+----+--------+ | A | Male | 25 |51.4-57.5|55.2| 3.34 | | | Female | 25 |49.3-54.9|51.6| 3.12 | | B | Male | 20 |51.0-57.1|55.4| 2.44 | | | Female | 21 |47.3-54.9|51.2| 3.52 | | C | Male | 6 |54.5-56.2|55.2| .... | | | Female | 6 |50.0-52.9|51.6| .... | | D | Male | 17 |52.9-58.2|55.4| 2.64 | | | Female | 14 |48.5-56.6|52.1| 4.16 | | E | Male | 10 |50.9-56.9|55.1| 3.40 | | | Female | 7 |49.6-54.5|51.6| .... | | F | Female | 2 |51.9-52.6|52.3| .... | +------------+-----------+---------+---------+----+--------+

A.--225 specimens: Dorsum mottled brown and cream, usually with a dark spot between the eyes and one or two dark V-shaped marks with the apex anteriorly on the back; 55 of these have a narrow cream-colored line from the tip of the snout to the vent and thence onto the posterior surfaces of the thighs. All are pustulate above; in most specimens the pustules form no pattern, but in some they tend to form a V in the scapular region.

B.--41 specimens: Dorsum pale tan or cream-color with brown mottling on flanks; a brown interorbital bar and a brown chevron in scapular region. Dorsum irregularly pustulate; in some specimens the pustules tend to form a V in the scapular region.

C.--12 specimens: Dorsum colored like "A", but having a broad yellow stripe narrowly bordered by black from the tip of the snout to the vent; in some specimens there is a narrow yellow stripe on the posterior surfaces of the thighs. The dorsum is irregularly pustulate.

D.--31 specimens: Dorsum variably streaked with cream-color or pale tan and brown; usually a broad cream-colored stripe from eyelid to groin bordered laterally by a somewhat narrower brown stripe; middorsal area cream-color and separated from dorsolateral cream-colored stripe by a brown stripe, or middorsal area brown with a cream-colored or yellow, narrow stripe from tip of snout to vent; a dark stripe from tympanum to flank; dorsal surfaces of heels creamy white to pale orange; anal patch brown. A dermal ridge from posterior edge of eyelid to rump; another ridge extends posteromedially from the eyelid; scattered pustules on the dorsum in some specimens.

E.--17 specimens: A narrow dark stripe from snout, through nostril and eye, over tympanum, to vent, enclosing a unicolor dorsum (reddish tan to yellowish tan in life); heels pale tan or yellow above; anal patch black. A faint dermal ridge from posterior edge of eyelid to rump, or part way to rump.

F.--2 specimens: Mottled brown and cream-color above; upper lips and upper arms white. A dermal fold from posterior edge of eyelid to rump; scattered pustules on dorsum.

Some of these color variants are assignable to names proposed by Taylor: "A" and "B" undoubtedly are _M. pygmaeus_ (Taylor, 1936a); "C" probably is _M. pygmaeus_; "D" is referable to _M. minimus_ (Taylor, 1940d) in most characteristics, although the coloration is more nearly like that of _M. lineatissimus_ (Taylor, 1941a), a larger species characterized by a relatively long hind limb; "E" apparently is _M. imitator_ (Taylor, 1942b); "F" is _M. albolabris_ (Taylor, 1940d). Examination of series of these frogs from other parts of Mexico shows a similar composition of color variants. Of 78 specimens from the Rio Sarabia and the village of Sarabia in Oaxaca (UMMZ 115428-37), 57 are "A," six are "D," three are "E," and 12 are "F"; of 22 specimens from Teapa, Tabasco (UMMZ 113829), 11 are "A," five are "D," two are "E," and four are "F"; of 33 specimens from Potrero Viejo, Veracruz (USNM 115447-58, 115461-71, 116840-2, 116864-70), ten are "A," 13 are "E," and ten are "F"; of 31 specimens from La Esperanza, Chiapas (USNM 115477-9, 116827-39, 116849-63), 28 are "A" and four are "F."

It is highly doubtful if these color variants are actually distinct species. Goin (1950 and 1954) in his studies of inheritance of color pattern in West Indian species of the genus _Eleutherodactylus_ has shown that similar color pattern variants come from the same clutch of eggs; furthermore, Goin has worked out the genetic ratios of certain of these variants. Heathwole (_in litt._) obtained "normal" specimens and individuals having a broad middorsal stripe ("C" in figure 9) from a clutch of eggs of _Eleutherodactylus gollmeri_. The presence of a broad middorsal yellow stripe is common in _Eleutherodactylus rugulosus_.

Perhaps the most interesting aspect of variability in color pattern in Mexican eleutherodactylids is the parallelism between members of the _Eleutherodactylus rhodopis_-group and some members of _Microbatrachylus_. In the former group there are white-lipped individuals (_Eleutherodactylus beatae_ Boulenger), individuals having a unicolor reddish or yellowish dorsum (_E. dorsoconcolor_ Taylor), and individuals having a dorsal pattern of irregular longitudinal brown and cream-colored streaks (_E. venustus_ Guenther). In the humid forests of southern Veracruz, northern Oaxaca, and Chiapas members of both groups occur sympatrically. A proper understanding of the evolutionary significance of these variants in the two groups, as well as proper allocation of the presently recognized species, must await experimental evidence based on studies of the inheritance of color pattern. Nevertheless, at present it is apparent that certain characters, especially the nature of the dermal folds and pustules, and the color pattern, are of little taxonomic value in distinguishing "species" of _Microbatrachylus_. The data derived from a study of the large series from Arteaga, together with that from the other series examined, suggests that _Microbatrachylus albolabris_, _imitator_, _minimus_, and _pygmaeus_ are morphotypes of one species. Of these names, _pygmaeus_ is the oldest. Consequently _Microbatrachylus pygmaeus_ has been used here for the series from Arteaga.

Although _Microbatrachylus hobartsmithi_, a species distinguished from all of the above by the presence of tubercles on the outer edge of the tarsus, is known from Michoacan northward into Nayarit, _Microbatrachylus pygmaeus_ previously has not been known north of Guerrero, where it occurs in habitats similar to that in which it was collected at Arteaga.

~Eleutherodactylus augusti cactorum~ Taylor

_Eleutherodactylus cactorum_ Taylor, Univ. Kansas Sci. Bull.,
25:391, July 10, 1939.--20 miles northwest of Tehuacan,
Puebla, Mexico.

_Eleutherodactylus augusti cactorum_, Zweifel, Amer. Mus.
Novitates, 1813:20, December 23, 1956.

Cheran; Coalcoman; Uruapan.

The few specimens indicate that this species occurs at moderate to high elevations in the state. The specimens from Cheran and Uruapan were obtained in pine forests; the specimen from Coalcoman was found on a rocky hillside covered with dense forest and located about 100 meters below the lower limits of the pine forest in the area. A specimen from Rancho Reparto (elevation 1850 meters) on the west slope of Cerro Barolosa was lost.

The specimen from Coalcoman (UMMZ 104728) is a juvenile having a snout-vent length of 25.0 mm. In life it was tan above, mottled with olive-green. The ventral surfaces were gray; the hind limbs were distinctly barred with yellow and brown, and the lips were barred with yellow and black.

~Eleutherodactylus occidentalis~ Taylor

_Eleutherodactylus occidentalis_ Taylor, Proc. Biol. Soc.
Washington, 54:91, July 31, 1941.--Hacienda El Florencio,
Zacatecas, Mexico.

Arteaga (2); Cascada Tzararacua; Coalcoman (2); 19 km. SW of
Coire (3); La Placita (7); Los Reyes; Ostula (4); Pomaro
(2).

The locality records for this species suggest that it is a member of a group of animals, the distribution of which includes the western part of the Mexican Plateau and the Pacific lowlands. In Michoacan this frog has been collected in pine-oak forest at Cascada Tzararacua and at Los Reyes, in arid scrub forest at Arteaga and Coalcoman, and in tropical semi-deciduous forest on the lower Pacific slopes of the Sierra de Coalcoman. On July 5, 1950, James Peters (1954:6) found calling males at La Placita.

Most of the specimens are immature; four adult males have snout-vent lengths of 30.9-33.0 (32.2) mm. In all specimens the first finger is noticeably longer than the second; the inner metatarsal tubercle is large, flat, and cream-colored, contrasting with the dark brown sole of the foot. When the hind limbs are adpressed, the heels broadly overlap. Characteristically, a dark line extends from the snout, through the eye, above the tympanum, to a point above the insertion of the forelimb. Usually there is a dark bar behind the tympanum, two dark brown bars from the eye to the mouth and thence onto the lower jaw, and another dark bar on the upper lip between the eye and nostril. One adult from Arteaga, an adult and a juvenile from La Placita, and one juvenile each from Coire, Ostula, and Pomaro, have the lower lip barred with dark brown and white, and have a white stripe extending the length of the upper lip. In life the dorsum varies from dark gray or olive-brown to tan or reddish brown.

This species belongs to a group containing two other populations that are currently recognized as species--_calcitrans_, known only from Omiltemi, Guerrero, and _mexicanus_, reported from the mountains of Oaxaca. Another apparently undescribed member of this group has been collected in the mountains of northern Puebla. The locality records indicate that the group inhabits the mountains on the periphery of the Mexican Plateau, except in western Mexico, where _Eleutherodactylus occidentalis_ extends to the Pacific lowlands.

~Eleutherodactylus rugulosus vocalis~ Taylor

_Eleutherodactylus vocalis_ Taylor, Univ. Kansas Sci. Bull.,
26:401, November 27, 1940.--Hacienda El Sabino, Michoacan,
Mexico.

Arteaga (10); El Sabino (8); Salitre de Estopilas (3);
Tumbiscatio (2); Tzitzio (2).

The distributional data on this frog in Michoacan indicate that it inhabits riparian situations in arroyos and canyons in the lower slopes of the Cordillera Volcanica and the Sierra de Coalcoman, where it has been taken at elevations only below 1100 meters.

The dorsal color of living individuals from Arteaga varied from dark gray and olive brown to tan and reddish brown. The iris was grayish brown. In contrast, individuals from Agua del Obispo, Guerrero, had pale golden eyes; specimens from Matias Romero, Oaxaca, had gold eyes heavily flecked with gray; and individuals from Volcan San Martin, Veracruz, had bronze eyes.

The use of the trinomial here is arbitrary. Frogs of the _Eleutherodactylus rugulosus_ group in Mexico (_rugulosus_, _avocalis_, and _vocalis_) exhibit only slight differences in size, proportions, and coloration (Duellman, 1958c:6). Furthermore, the named populations are allopatric. _Eleutherodactylus rugulosus vocalis_, as defined by Duellman (_loc. cit._), occurs in the foothills of the Sierra Madre Occidental and associated ranges from central Sinaloa southward into Michoacan.

~Tomodactylus angustidigitorum~ Taylor

_Tomadactylus angustidigitorum_ Taylor, Univ. Kansas Sci.
Bull., 26:494, November 27, 1940.--Quiroga, Michoacan,
Mexico.

Angahuan (6); Apo; Carapan (21); 19 km. S of Carapan (13);
Cerro Tancitaro (12); Cheran; Corupu (14); Cuseno Station
(14); Opopeo (3); Paracho (11); Paricutin (2); Patzcuaro
(3); Quiroga (59); San Juan de Parangaricutiro (16);
Tancitaro (25); Uruapan (8); Zacapu (11).

This species is indigenous to the pine-oak forests on the southern rim of the Mexican Plateau, and has been collected at elevations from 1500 to 2500 meters. Males have been observed to call from rocks, rock fences, clumps of grass, and low bushes; the call is a single "peep." At San Juan de Parangaricutiro numerous specimens were found in the daytime beneath adobe bricks and lava on the volcanic ash derived from Volcan Paricutin; at Paracho individuals were found by day beneath rocks in a pine forest.

In most specimens the dorsum is dark reddish brown, and the prominent inguinal glands are cream-color or pale orange (Pl. 3, Fig. 1). Of eight individuals collected at Paracho, one was reddish brown, two were pinkish tan, three were dark brown, and two were black.

~Tomodactylus fuscus~ Davis and Dixon

_Tomodactylus fuscus_ Davis and Dixon, Herpetologica,
11:157, July 15, 1955.--1.5 miles southeast of Huitzilac,
Morelos, Mexico.

Los Cantiles (2); 28 km. E of Morelia.

The range of this species includes the Sierra Ajusco in Mexico and Morelos and thence westward to the Serrania Ucareo in Michoacan. The specimen from 28 kilometers east of Morelia was found in an oak forest on a steep hillside at an elevation of 2100 meters. One from Los Cantiles was calling from a steep cliff at an elevation of 2200 meters in pine-oak forest. This specimen (UMMZ 119156) in life had a pale olive-brown dorsum with irregular dark brown mottling and transverse bars on the limbs. The interorbital bar, the upper arms, and the tips of the dorsal pustules were pale orange; the iris was pale grayish gold (Pl. 3, Fig. 2).

~Tomodactylus nitidus nitidus~ (Peters)

_Liuperus nitidus_ Peters, Monats. Akad. Wiss. Berlin, p.
878, 1869.--Izucar de Matamoras, Puebla, Mexico.

_Tomodactylus amulae_ Guenther, Biologia Centrali-Americana,
Reptilia and Batrachia, p. 219, April, 1900.--Amula,
Guerrero, Mexico.

_Tomodactylus nitidus nitidus_, Dixon, Texas Jour. Sci.,
9:385, December, 1957.

Copuyo (15); Tuxpan (8); Tzitzio (11).

One specimen from Tzitzio (UMMZ 99155) was referred to _Tomodactylus nitidus petersi_ by Dixon (1957:390). A re-examination of this specimen, and examination of ten others from the same locality (UMMZ 121571) reveals that the relatively small size of the tympanum and absence of dense ventral spotting place these specimens closer to _T. nitidus nitidus_ than to _T. nitidus petersi_.

The specimens from Tuxpan (UMMZ 114303-4) had in life a gray to olive tan ground color with dark olive-green markings, bright yellow thighs with olive-green transverse bands, yellowish tan shanks with olive-green bars, yellow groin, white inguinal glands with black markings, grayish white belly with scattered brownish black spots in some specimens, and a deep golden iris (Pl. 4, Fig. 1). These specimens were found calling from bushes in a rocky field at an elevation of 1800 meters. The call is a high-pitched "pee-ee-eep."

~Tomodactylus nitidus orarius~ Dixon

_Tomodactylus nitidus orarius_ Dixon, Texas Jour. Sci.,
9:392, December, 1957.--4.5 miles southwest of Tecolapa,
Colima, Mexico.

La Placita (3); Pomaro.

These specimens, referred to _Tomodactylus petersi_ by Duellman (1954b:5), were included in _T. nitidus orarius_ by Dixon (1957:392). Color notes based on living individuals from Tecolapa, Colima (UMMZ 114312 and 116922), are: gray above mottled with brown; venter dirty white; anterior and posterior surfaces of thighs bright yellow; iris pale golden (Pl. 4, Fig. 2). The call is a soft "braa" usually followed by three high notes: "braaa-eep-ee-eep." In Michoacan this subspecies has been found only in the coastal region and the lower foothills of the Sierra de Coalcoman, an area in which it replaces _Tomodactylus nitidus petersi_. This is the only _Tomodactylus_ known to inhabit coastal lowlands.

~Tomodactylus nitidus petersi~ Duellman

_Tomodactylus petersi_ Duellman, Occ. Pap. Mus. Zool. Univ.
Michigan, 560:5, October 22, 1954.--Coalcoman, Michoacan,
Mexico.

_Tomodactylus nitidus petersi_, Dixon, Texas Jour. Sci.,
9:390, December, 1957.

Aguililla; Apatzingan (8); Cascada Tzararacua: Charapendo
(5); Coalcoman (5); 18 km. E of Dos Aguas (6); El Sabino
(5); La Playa (2); Jiquilpan; Uruapan (2); Volcan Jorullo;
Zamora.

In life, specimens from Apatzingan (UMMZ 114308-9) varied in dorsal color from grayish tan to pale brown; the dorsal markings were olive green. The thighs and groin were yellowish orange; the iris was pale golden, and the vocal sac was purplish gray (Pl. 5, Fig. 1). Measurements for 13 adult males from the Tepalcatepec Valley are: snout-vent length, 21.9-26.8 (24.3); tibia length, 8.4-9.9 (9.3); head width, 7.2-9.2 (7.8); head length, 7.6-8.7 (8.2).

At Apatzingan and Charapendo in the Tepalcatepec Valley males were found calling from rocks and bushes in open arid tropical scrub forest. The call, a triple note "peep-ee-eep," is repeated once every 90 to 135 seconds. _Tomodactylus nitidus petersi_ probably ranges throughout the Tepalcatepec Valley and surrounding foothills. Dixon (1957:392) referred the specimens from Zamora, Jiquilpan, and Uruapan to this subspecies. Uruapan is near the lower limits of the pine forest on the slopes of the Cordillera Volcanica; Zamora and Jiquilpan are on a low part of the Mexican Plateau southeast of Lago de Chapala.

~Tomodactylus rufescens~ Duellman and Dixon

_Tomodactylus rufescens_ Duellman and Dixon, Texas Jour.
Sci., 11:78, March, 1959.--Dos Aguas, Michoacan, Mexico.

Dos Aguas (14); 18 km. E of Dos Aguas (6).

Fourteen specimens from the pine-oak forests around Dos Aguas (UMMZ 118503-10, 121498-9) have reddish brown dorsal color and a narrow cream-colored middorsal line (Pl. 5, Fig. 2). Twelve of these specimens are adult males having snout-vent lengths of 20.7 to 24.6 (22.5) mm. One female has a snout-vent length of 24.8 mm., and one juvenile has a snout-vent length of 14.5 mm. Six specimens are from a region of mixture of pine-oak forest and arid tropical scrub forest at 18 kilometers east of Dos Aguas (UMMZ 121497, 121500). All are males having snout-vent lengths of 18.0 to 22.6 (20.7) mm. The dorsum is tan marked with black; the thighs are yellowish orange.

The specimens from 18 kilometers east of Dos Aguas were found on July 22, 1960, by Floyd L. Downs and John Winklemann, who collected calling males of _Tomodactylus rufescens_ and _Tomodactylus nitidus petersi_ at the same locality. Downs (_personal communication_) stated the call was a single note. At Dos Aguas I heard _T. rufescens_ give two calls, one a single "peep," the other a triple note--"pee-ee-eep."

In the higher parts of the Sierra de Coalcoman _Tomodactylus rufescens_ seems to fill the same niche as _T. angustidigitorum_ does in the Cordillera Volcanica. At lower elevations in their respective mountain ranges the species occur sympatrically with _T. nitidus petersi_.

~Diaglena reticulata~ Taylor

_Diaglena reticulata_ Taylor, Univ. Kansas Sci. Bull.,
28:60, May 15, 1942.--Cerro Arenal, Oaxaca, Mexico.

Nueva Italia (3); Ostula (7).

Until recently frogs of the genus _Diaglena_ were known only from a few specimens from southern Sinaloa (_Diaglena spatulata_) and from the Pacific lowlands of the Isthmus of Tehuantepec (_Diaglena reticulata_). Peters (1955a) reported specimens from Ostula, Michoacan, and compared these specimens with one _D. reticulata_ from Tehuantepec, Oaxaca, and four _D. spatulata_ from Sinaloa. This comparison showed that the specimens from Michoacan, although showing some minor differences from _D. reticulata_, are closer to that species than to _D. spatulata_. Subsequent to Peters' work, series of both species of _Diaglena_, including additional specimens from Michoacan and from Colima, have been collected, and a more qualified comparison is now possible.

In comparing specimens of _D. spatulata_ from southern Sinaloa (UMMZ 115322) with specimens of _D. reticulata_ from Tehuantepec, Oaxaca (UMMZ 115321), the differences noted by Taylor (1942c:60) were found to be constant. But specimens from Ostula, Michoacan (UMMZ 104418), and five individuals from Colima (TNHC 26379-83) were found to be intermediate in certain characters. The skin of the dorsum in _D. reticulata_ is granular; that in _D. spatulata_ is smooth. The skin in specimens from Ostula and Colima is slightly granular. The dorsal ground color of _D. reticulata_ is yellowish brown with dark reticulations; the dorsal ground color of _D. spatulata_ is olive-green. Specimens from Ostula and Colima most closely resemble those from Tehuantepec in coloration, but the reticulations are more coarse, and the ground color has an olive-green tint. _Diaglena reticulata_ also differs from _D. spatulata_ in having a larger over-all size, slightly broader head, a narrower interorbital distance, and a more pointed snout with a deeper labial shelf (Table 4). The specimens from Ostula and Colima are intermediate between _D. reticulata_ from Oaxaca and _D. spatulata_ from Sinaloa in body proportions.

Of three specimens from the Tepalcatepec Valley (JRD 5991-3), only two are suitable for measuring. These specimens are smaller than adults from the coastal areas and have broader heads and snouts, but narrower interorbital distances, than specimens in the other samples (Table 4). The texture of the skin is like that of specimens from Ostula and Colima. The coloration resembles that of _D. reticulata_, but the reticulations are bold and form indistinct bands on the hind limbs.

TABLE 4.--COMPARISON OF FOUR CHARACTERS IN FIVE SAMPLES OF DIAGLENA. (ALL DATA ARE FOR MALES; MEANS GIVEN IN PARENTHESES BELOW RANGES.)

+-----------------+---------+----------+----------+---------+-----------+ | | | | Head | Inter- |Internarial| | | | | width | orbital | distance | | | Number |Snout-vent| |distance | | | Locality | of | length |----------+---------+-----------+ | |specimens| |Snout-vent| Head | Head | | | | | length | width | width | +-----------------+---------+----------+----------+---------+-----------+ | Oaxaca | 9 |71.1-87.5 |25.4-29.1 |63.0-71.4| 11.9-13.8 | | | | (80.7) | (27.9) | (67.1) | (12.9) | +-----------------+---------+----------+----------+---------+-----------+ | Coast of | 5 |72.0-79.2 |24.3-27.2 |67.0-73.8| 13.7-14.4 | | Michoacan | | (74.8) | (25.6) | (71.4) | (14.1) | +-----------------+---------+----------+----------+---------+-----------+ | Colima | 4 |71.7-79.6 |26.1-28.6 |70.5-75.3| 16.0-17.9 | | | | (74.8) | (27.4) | (72.0) | (16.6) | +-----------------+---------+----------+----------+---------+-----------+ | Tepalcatepec | 2 |63.0-65.4 |28.3-32.2 |57.3-62.4| 17.0-20.2 | | Valley | | (64.2) | (30.3) | (59.9) | (18.6) | +-----------------+---------+----------+----------+---------+-----------+ | Sinaloa | 11 |71.9-81.3 |24.0-27.3 |70.5-78.1| 15.0-17.3 | | | | (77.3) | (25.7) | (73.4) | (16.1) | +-----------------+---------+----------+----------+---------+-----------+

All specimens from Michoacan and Colima more closely approach _Diaglena reticulata_ than _D. spatulata_. The acquisition of additional specimens, especially from the area between Sinaloa and Colima and from Guerrero, is necessary to determine the relationships among the various populations known at present. Both species of _Diaglena_ inhabit tropical scrub forest; none has been found in the more humid and tropical semi-deciduous forests. Humid forest replaces the scrub forest in the lowlands of southern Nayarit and northern Jalisco; possibly this forest acts as a barrier to the distribution of _Diaglena_ and thus serves as a divider between the ranges of _D. spatulata_ to the north and _D. reticulata_ to the south.

~Pternohyla fodiens~ Boulenger

_Pternohyla fodiens_ Boulenger, Ann. Mag. Nat. Hist., ser.
5, 10:326, 1882.--Presidio, Sinaloa, Mexico.

Nueva Italia (2).

These specimens (JRD 5994-5) were found on the road near Nueva Italia during a heavy rain on the night of August 25, 1960, by James R. Dixon. Both are females having snout-vent lengths of 64.0 and 59.0 mm. They are typical of the species as it is known from Sinaloa, Nayarit, Jalisco, and Colima.

These specimens constitute the southernmost record for the species, which ranges in semi-arid habitats from southern Arizona southward along the Pacific lowlands of Mexico to Colima and inland on the Mexican Plateau in Jalisco.

~Phyllomedusa dacnicolor~ Cope

_Phyllomedusa dacnicolor_ Cope, Proc. Acad. Nat. Sci.
Philadelphia, 16:181, September 30, 1864.--Colima, Colima,
Mexico. Funkhouser, Occ. Pap. Nat. Hist. Mus. Stanford
Univ., 5:37, April 1, 1957.

_Agalychnis alcorni_ Taylor, Copeia, no. 2:31, June 2,
1952.--Rio Tepalcatepec, 17 miles south of Apatzingan,
Michoacan, Mexico.

_Agalychnis dacnicolor_, Duellman, Herpetologica, 13:29,
March 30, 1957.

_Phyllomedusa alcorni_, Funkhouser, Occ. Pap. Nat. Hist.
Mus. Stanford Univ., 5:30, April 1, 1957.

Aguililla (13); Apatzingan (7); Charapendo; Coahuayana (3);
Coalcoman (54); El Sabino; Huetamo Road (2); La Orilla; La
Placita; Nueva Italia (4); 32 km. E of Neuva Italia (2); Rio
Cancita, 14 km. E of Apatzingan; Rio Tepalcatepec, 27 km. S
of Apatzingan; Salitre de Estopilas (2); Tzitzio (4).

This large tree frog has been found only in the lowlands below elevation of about 1000 meters, usually in arid tropical scrub forest. Calling males were heard on rainy nights throughout the rainy season; in nearly every instance both males and females were found in low trees and bushes. On summer nights when there had been no rain, adults were found sitting on bushes in the scrub forest.

At Coalcoman on July 1, 1955, a chorus was heard at midday. About forty _Phyllomedusa dacnicolor_ were found in one guayava bush at the edge of a recently dried pond. Individual males were calling; clasping males were silent. The call is a barking groan. Fifteen individual egg masses were hanging from branches and leaves in tear-drop fashion. Each egg mass contained 100 to 350 pale green eggs, located only in the exterior part of the clear gelatinous mass. Two composite egg masses appeared to have been made up by egg deposition on the part of three to five females (Pl. 2, Fig. 2).

As shown by Duellman (1957a), the characters used by Taylor (1952) to diagnose _Phyllomedusa alcorni_ are sexually dimorphic. Funkhouser (1957) apparently was unaware of this sexual dimorphism, for she recognized _P. alcorni_ and _P. dacnicolor_ as distinct species.

~Phrynohyas inflata~ (Taylor)

_Acrodytes inflata_ Taylor, Univ. Kansas Sci. Bull., 30:64,
June 12, 1944.--La Venta, Guerrero, Mexico.

_Phrynohyas inflata_, Duellman, Misc. Publ. Mus. Zool. Univ.
Michigan, 96:19, February 1, 1956.

_Phrynohyas corasterias_ Shannon and Humphrey,
Herpetologica, 13:15, March 30, 1957.--4.8 miles east of San
Blas, Nayarit, Mexico.

Barranca de Bejuco.

One specimen of this large species was collected in 1951; it was found on a low branch in tropical semi-deciduous forest at an elevation of 65 meters. In life there were olive-gray blotches on a pale gray dorsum; the iris was a dark golden color.

This species, which is known from only a few specimens, seems to be restricted to the coastal lowlands and low foothills from Guerrero northward to Nayarit. Shannon and Humphrey (1957) described _Phrynohyas corasterias_ from Nayarit. Their description was based on a small female having a snout-vent length of 34.4 mm. The new species was diagnosed as differing from _P. inflata_ in having less webbing on the feet, a poorly developed supratympanic fold, a more pustulate dorsum, and marked differences in dorsal pattern, color, and nature of antebrachial banding. The significance of the webbing was questioned by Shannon and Humphrey. The nature of the supratympanic fold and dorsal pustules changes with age (Duellman, 1956a:31). _Phrynohyas inflata_ is known to attain a snout-vent length of 95 mm. Dermal structures that undergo ontogenetic change are of little importance in comparing a juvenile with a large adult. The only significant difference in color pattern between _P. inflata_ and _P. corasterias_ is the presence of wide transverse bands on the limbs of the latter. In this respect _P. corasterias_ approaches _P. latifasciata_, a species known only from two specimens from southern Sinaloa. The acquisition of additional specimens from Jalisco, Nayarit, and Sinaloa may show that _P. inflata_ and _P. latifasciata_ are conspecific, as suggested by Duellman (1956a:21). Nonetheless, the specimen on which the description of _P. corasterias_ was based is not sufficiently different from the known specimens of _P. inflata_ to warrant specific recognition.

~Hyla arenicolor~

_Hyla arenicolor_ Cope, Jour. Acad. Nat. Sci. Philadelphia,
ser. 2, 6:84, July, 1866.--Northern Sonora, Mexico. Type
locality restricted to Santa Rita Mountains, Pima County,
Arizona, by Smith and Taylor (1950a:354).

Agua Cerca; Cascada Tzararacua (3); Chinapa; Cojumatlan; Dos
Aguas; El Sabino (25); El Espinal; Lago de Camecuaro;
Lombardia (2); Tupataro; Zinapecuaro.

Altitudinally this frog ranges from 500 to 2100 meters; although the environments in which it has been found vary from open arid tropical scrub forest to pine forest, it usually is found near rocky streams in these habitats. There is great disparity in size between specimens from the mountains and those from the Tepalcatepec Valley. Seven males from elevations in excess of 1400 meters have an average snout-vent length of 34.7 mm.; nine from elevations below 1000 meters have an average snout-vent length of 49.1 mm. In life a male collected at night at Lombardia (UMMZ 112846) had dark brown spots on a grayish brown dorsum; the groin, anterior and posterior surfaces of the thighs, and ventral surfaces of the hind limbs and palms were yellowish orange. The belly and tips of digits were white; the vocal sac was purplish brown, and the iris was dark grayish gold. In contrast, a specimen obtained in the daytime at Chinapa (UMMZ 119204) had indistinct gray spots on a pale ashy gray dorsum; the flash colors were yellow. After dark the spots were dark olive-brown on a grayish brown dorsum.

Two males were found calling from a rocky stream near Lombardia on July 12, 1955. The call is a nasal "ah-ah-ah-ah."

~Hyla baudini~ Dumeril and Bibron

_Hyla baudinii_ Dumeril and Bibron, Erpetologie generale,
vol. 8:564, 1841.--Mexico. Type locality restricted to
Cordoba, Veracruz, Mexico, by Smith and Taylor (1950a:346).

Aguililla (5); Apatzingan (30); Arteaga; Buena Vista;
Charapendo; Coahuayana; Cofradia (4); El Sabino (12); La
Placita; La Playa; Maruata; Nueva Italia (3); 32 km. E of
Nueva Italia (2); Ostula (4); Rio Tepalcatepec, 25 km. S of
Apatzingan (3); Salitre de Estopilas; San Jose de la Montana
(2); Tumbiscatio; Tzitzio.

This tree frog is widespread in the coastal lowlands and in the Tepalcatepec Valley up to elevations of about 1200 meters. It is found in numbers in the early part of the rainy season, at which time males were heard calling from bushes and trees along ditches and temporary ponds. The call is a loud nasal "waank-waank-waank." One individual that was emitting a long and unusually high-pitched call was found to have one hind limb engulfed by a _Leptodeira maculata_.

When active at night these frogs usually are pale tan to reddish brown above with dark brown markings. A specimen found sitting on a maguey plant in the daytime was pale ashy gray with a pale green upper lip.

~Hyla bistincta~ Cope

_Hyla bistincta_ Cope, Proc. Amer. Philos. Soc., 17:87,
1877.--Veracruz, Mexico. Type locality restricted to
Acultzingo, Veracruz, Mexico, by Smith and Taylor
(1950a:346).

Cerro San Andres; Dos Aguas (2); Los Conejos (3); Uruapan
(50).

In the Parque Nacional at Uruapan this species was found in abundance during the day. The frogs hide in an entanglement of vines and vegetation overhanging several small spring-fed streams. Tadpoles were in the rocky streams, and metamorphosing young were on vegetation at the edges of the streams.

In life the dorsum is greenish tan with brown mottling; in some individuals the entire dorsum is dark chocolate brown. The flanks are pale lemon yellow barred with lavender-brown. Notes on the color of a living frog from Dos Aguas (UMMZ 119193) are: Dorsal ground color a medium shade of brown with dark brown flecks; flanks black with silvery white and pale yellow spots; belly pale yellowish white; throat mottled with grayish brown; iris pale copper color.

Description of Tadpole: Body somewhat depressed; maximum width of body slightly more than one-half of body length. Nostrils placed dorsolaterally and directed anteriorly, situated about midway between tip of snout and eye. Eyes of moderate size, dorsolateral in position and directed upwards. Tail about twice as long as body, thrice as long as deep, and tapering gradually to a rounded tip. Tail-musculature not extending to tip of tail fin. Spiracle sinistral, lateral, and situated at midbody. Vent dextral; the cloacal tube extending along ventral part of tail for a distance equal to about one-eighth of body length (Fig. 8). Average body length of six tadpoles with small hind limb buds, 19.5 mm.; tail length, 38.3 mm. Mouth ventral, its width equal to about two-thirds of greatest width of body. Lips bordered by two rows of small papillae; row of larger papillae between upper lip and outer upper tooth-row, similar row between lower lip and outer lower tooth-row; laterally these rows degenerating into numerous small papillae. Horny beaks well developed; upper beak moderately arched and deeply indented; lower beak slightly indented. Serrations of beaks blunt and peglike, moderately developed on both beaks, but slightly stronger on lower one. Tooth-rows 2/3; upper rows nearly equal in length and slightly longer than lower rows, which are subequal in length; inner upper tooth row interrupted medially by rounded notch; inner lower tooth-row turned downward laterally; teeth in all rows about equal in size, but decreasing in length laterally (Fig. 9).

Color in formalin: pale grayish brown dorsally and laterally; pale gray ventrally; tail-musculature brown; tail-fin translucent with scattered melanophores most numerous on upper fin.

In most details these tadpoles resemble those of _Hyla robertsorum_ described by Rabb and Mosimann (1955).

Four metamorphosing young have snout-vent lengths of 23.0-23.5 (23.2); a completely metamorphosed individual has a snout-vent length of 24.8 mm.

In Michoacan this stream-breeding hylid occurs at elevations of 1,600 to 2,400 meters in the Sierra de Coalcoman and in the mountains rising from the Mexican Plateau.

~Hyla eximia~ Baird

_Hyla eximia_ Baird, Proc. Acad. Nat. Sci. Philadelphia,
7:61, October 20, 1854.--Valley of Mexico. Type locality
restricted to Coyoacan, Distrito Federal, Mexico, by Smith
and Taylor (1950a:329).

_Hyla microeximia_ Maslin, Herpetologica, 13:81, July 10,
1957.--3 miles northwest of Jocotepec, Jalisco, Mexico.

Ciudad Hidalgo (36); Cuitzeo; 29 km. NW of Jacona; Jiquilpan
(2); Lago de Camecuaro (2); Lago de Patzcuaro (129); Los
Reyes; Morelia; Sahuayo (3); San Gregorio (63);
Tangamandapio (4); Temazcal (26); Tupataro; Tuxpan (15);
Undameo (2); Uruapan (20); Zacapu; Zamora (27); Zinapecuaro
(10).

More than 80 per cent of the specimens from Michoacan have brown spots between the lateral and dorsolateral dark stripes, and more than 50 per cent have spots between the dorsolateral stripes, at least posteriorly. In comparison with specimens from the Valley of Mexico, those from Michoacan have more distinct dorsolateral stripes that extend farther anteriorly, sometimes to the eyelid, and in this respect are more nearly like those from Jalisco and Nayarit (Taylor, 1939b:425). Some specimens from the western part of Michoacan possess certain characters used by Maslin (1957:81) to distinguish _Hyla microeximia_ from _H. eximia_; nevertheless, the variation is such that two species cannot be distinguished in Michoacan. Four series of freshly preserved specimens have been studied in detail; in the discussion below they are arranged from west to east; the measurement is for snout-vent length of ten males from each sample:

_Zamora._--Twenty-two specimens (UMMZ 102083), 24.0-27.6
(26.1) mm. Dorsolateral dark stripe, or row of dashes,
present in all specimens; dark spots in lateral and dorsal
green fields; lateral dark stripe confluent with
dorsolateral stripe posteriorly in 18 specimens; white line
not extending to groin.

_Temazcal._--Thirty-five specimens (UMMZ 119162), 26.5-31.1
(28.2) mm. Dorsolateral dark stripe of row of spots present
only posteriorly in most; both dorsolateral stripes and
dorsal spots lacking in four specimens; heavy spotting
dorsally in three others; lateral and dorsolateral dark
stripes confluent posteriorly in three; lateral white stripe
extending to groin in 16 specimens.

_Ciudad Hidalgo._--Thirty-six specimens (UMMZ 119163),
26.4-30.9 (28.2) mm. Dorsolateral dark stripe or row of
spots present only posteriorly in most; no brown spots in
the green fields of many specimens; large brown inguinal
spot in most specimens; heavy spotting dorsally in four;
lateral and dorsolateral dark stripes confluent posteriorly
in five; lateral white line extending to groin in most
specimens.

_Tuxpan._--Fifteen specimens (UMMZ 115227), 28.7-33.0 (30.5)
mm. Dorsolateral dark stripe or row of dashes in all
specimens; dark spots in lateral green fields, at least
posteriorly in most; dark spots posteriorly in the dorsal
green field in five; lateral dark stripe separated from
dorsolateral stripe in all specimens; lateral white line
extends to the groin in all specimens.

As can be seen from the above descriptions, the distinguishing characters of _Hyla microeximia_--confluence of lateral and dorsolateral dark stripes posteriorly, extent of lateral white stripe, and distribution of dark spots dorsally--are found in individuals from all of the populations sampled. In the samples from western Michoacan there is a higher incidence of _microeximia_-like frogs than in those from other parts of the state. _Hyla eximia_ is a wide-ranging species varying greatly geographically and individually. A thorough review of the species and related members of the _Hyla eximia_-group is necessary before certain populations can justifiably be segregated as subspecies or species.

In Michoacan _Hyla eximia_ has been collected in mesquite-grassland, pine-oak forest, and cultivated areas on the Mexican Plateau from 1500 to 2300 meters; apparently it is absent from the Sierra de Coalcoman. This is the most abundant frog on the southern part of the Mexican Plateau; in the rainy season breeding choruses are found in temporary pools and in the marshes adjacent to the permanent lakes.

~Hyla lafrentzi~ Mertens and Wolterstorff

_Hyla lafrentzi_ Mertens and Wolterstorff, Zool. Anz.,
84:235, August 25, 1929.--Desierto de los Leones, Distrito
Federal, Mexico.

Cerro San Andres (26); Opopeo (9).

In March, 1949, James A. Peters collected this species at elevations of 2400 to 2800 meters on the west slope of Cerro San Andres. The frogs were found beneath logs and rocks in a damp canyon in coniferous forest. Among the juveniles in this series is a completely transformed individual (UMMZ 102093) having a snout-vent length of 14.5 mm. Five adults have snout-vent lengths of 36.2-39.5 (38.0) mm. _Hyla lafrentzi_ has noticeably longer hind limbs than _H. eximia_; in the former, when the hind limb is brought forward along the body, the tibiotarsal articulation extends to the snout. There are dark transverse bands on the hind limbs; the dorsolateral stripe is broken into an anterior and a posterior segment, and the latter is narrowly bordered by white in most specimens.

_Hyla lafrentzi_ occurs at higher elevations than any other frog in Michoacan; the locality records from throughout the range indicate that it is restricted to pine and pine-fir forests. In these habitats it replaces _Hyla eximia_, which inhabits the lower pine-oak forests and mesquite-grassland on the Mexican Plateau. Ponds are absent at places where _Hyla lafrentzi_ has been collected; possibly the eggs are laid in streams.

~Hyla smaragdina~ Taylor

_Hyla smaragdina_ Taylor, Copeia, No. 1:18, March 30,
1940.--6 kilometers east of Cojumatlan, Michoacan, Mexico.

_Hylella azteca_ Taylor, Proc. Biol. Soc. Washington, 56:49,
June 16, 1943.--Tepoztlan, Morelos, Mexico.

Cojumatlan (30); Copuyo (7); 18 km. E of Dos Aguas (22);
Ostula (8); Pomaro (3); Sahuayo; Salitre de Estopilas (7).

Taylor (1940a:18) diagnosed this species as having few or no vomerine teeth, no vocal sac, a rather broad and flat head, two large tubercles below the anus, a granular venter, and a green dorsum in life. The specimens on which the description was based are either immature or non-breeding individuals; all were collected from bromeliads growing on cacti near Cojumatlan. Another small, flat-headed hylid from Tepoztlan, Morelos, was described and diagnosed by Taylor (1943b:49) as differing from _Hyla smaragdina_ in having a vocal sac and a broader head. This specimen was named _Hylella azteca_. Specimens from the coastal region of Michoacan and Colima were referred to _Hylella azteca_ by Peters (1954:7) and Duellman (1958c:8).

Comparison of topotypic _Hyla smaragdina_ and the holotype of _Hylella azteca_ (UIMNH 25044) with the several series of specimens from Michoacan has resulted in the conclusion that all pertain to only one species. Although the type series of _Hyla smaragdina_ consists of immature specimens, the males in that series do possess vocal sacs. Since these were not breeding individuals, the sacs are not well developed. The characters of the anal tubercles and the relative width of the head are of no value in separating the two species. The apparently aestivating individuals comprising the type series of _Hyla smaragdina_, and the type of _Hylella azteca_, which also was found in a bromeliad, were green in life. Of the calling males found on the coast of Michoacan, most were yellowish tan when found; two were pale green, but soon changed to pale tan. Calling males from Copuyo and Dos Aguas were pale yellowish tan. Therefore the color of the dorsum is of little significance in distinguishing the two named populations.

Males of _Hyla smaragdina_ have been found calling in the months of June and July from rocky streams; the call is a nasal "haah-haah-haah," repeated quickly and constantly for as long as 30 seconds. As pointed out by Duellman (1958c:9), this breeding behavior is unlike that suggested by Taylor (1943b:51). In Michoacan _Hyla smaragdina_ has been found in tropical semi-deciduous forest, oak forest, and mesquite-grassland at elevations from 150 to 1500 meters.

~Hyla smithi~ Boulenger

_Hyla smithi_ Boulenger, Zool. Rec. Reptilia and Batrachia,
38:33, 1902.--Cuernavaca, Morelos, Mexico.

Aguililla (14); Apatzingan (104); Arteaga; Charapendo (5);
Coalcoman (11); El Sabino (44); La Playa (6); Lombardia (2);
Nueva Italia (8); Playa Azul; Salitre de Estopilas (2).