Chapter I: Part 1

UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY

VOLUME 1 1946-1950

EDITORS

E. RAYMOND HALL DONALD S. FARNER DONALD F. HOFFMEISTER H. H. LANE A. BYRON LEONARD EDWARD H. TAYLOR ROBERT W. WILSON

MUSEUM OF NATURAL HISTORY UNIVERSITY OF KANSAS LAWRENCE, KANSAS 1950

MUSEUM OF NATURAL HISTORY UNIVERSITY OF KANSAS LAWRENCE, KANSAS

PRINTED BY FERD VOILAND, JR., STATE PRINTER TOPEKA, KANSAS 1950

23-2413

CONTENTS

1. The pocket gophers (genus Thomomys) of Utah. By Stephen
D. Durrant. Pp. 1-82, 1 figure in text. August 15, 1946.

2. The systematic status of Eumeces pluvialis Cope, and
noteworthy records of other amphibians and reptiles from
Kansas and Oklahoma. By Hobart M. Smith. Pp. 85-89. August
15, 1946.

3. The tadpoles of Bufo cognatus Say. By Hobart M. Smith.
Pp. 93-96, 1 figure in text. August 15, 1946.

4. Hybridization between two species of garter snakes. By
Hobart M. Smith. Pp. 97-100. August 15, 1946.

5. Selected records of reptiles and amphibians from Kansas.
By John Breukelman and Hobart M. Smith. Pp. 101-112. August
15, 1946.

6. Kyphosis and other variations in soft-shelled turtles. By
Hobart M. Smith. Pp. 117-124, 3 figures. July 7, 1947.

7. Natural history of the prairie vole (Mammalian genus
Microtus). By E. W. Jameson, Jr. Pp. 125-151, 4 figures in
text. October 6, 1947.

8. The postnatal development of two broods of great horned
owls (Bubo virginianus). By Donald F. Hoffmeister and Henry
W. Setzer. Pp. 157-173, 5 figures in text. October 6, 1947.

9. Additions to the list of the birds of Louisiana. By
George H. Lowery, Jr. Pp. 177-192. November 7, 1947.

10. A check-list of the birds of Idaho. By M. Dale Arvey.
Pp. 193-216. November 29, 1947.

11. Subspeciation in pocket gophers of Kansas. By Bernardo
Villa R. and E. Raymond Hall. Pp. 217-236, 2 figures in
text. November 29, 1947.

12. A new bat (Genus Myotis) from Mexico. By Walter W.
Dalquest and E. Raymond Hall. Pp. 237-244, 6 figures in
text. December 10, 1947.

13. Tadarida femorosacca (Merriam) in Tamaulipas, Mexico. By
Walter W. Dalquest and E. Raymond Hall. Pp. 245-248, 1
figure in text. December 10, 1947.

14. A new pocket gopher (Thomomys) and a new spiny pocket
mouse (Liomys) from Michoacan, Mexico. By E. Raymond Hall
and Bernardo Villa-R. Pp. 249-256, 6 figures in text. July
26, 1948.

15. A new hylid frog from eastern Mexico. By Edward H.
Taylor. Pp. 257-264, 1 figure in text. August 16, 1948.

16. A new extinct emydid turtle from the Lower Pliocene of
Oklahoma. By Edwin C. Galbreath. Pp. 265-280, 1 plate.
August 16, 1948.

17. Pliocene and Pleistocene records of fossil turtles from
western Kansas and Oklahoma. By Edwin C. Galbreath. Pp.
281-284, 1 figure in text. August 16, 1948.

18. A new species of heteromyid rodent from the Middle
Oligocene of northeast Colorado with remarks on the skull.
By Edwin C. Galbreath. Pp. 285-300, 2 plates. August 16,
1948.

19. Speciation in the Brazilian spiny rats (Genus
Proechimys, Family Echimyidae). By Joao Moojen. Pp. 301-406,
140 figures in text. December 10, 1948.

20. Three new beavers from Utah. By Stephen D. Durrant and
Harold S. Crane. Pp. 407-417, 7 figures in text. December
24, 1948.

21. Two new meadow mice from Michoacan, Mexico. By E.
Raymond Hall. Pp. 423-427, 6 figures in text. December 24,
1948.

22. An annotated check list of the mammals of Michoacan,
Mexico. By E. Raymond Hall and Bernardo Villa-R. Pp.
431-472, 2 plates, 1 figure in text. December 27, 1949.

23. Subspeciation in the kangaroo rat, Dipodomys ordii. By
Henry W. Setzer. Pp. 423-573, 27 figures in text, 7 tables.
December 27, 1949.

24. Geographic range of hooded skunk, Mephitis macroura,
with description of a new subspecies from Mexico. By E.
Raymond Hall and Walter W. Dalquest. Pp. 575-580, 1 figure
in text. January 20, 1950.

25. Pipistrellus cinnamomeus Miller 1902 referred to the
genus Myotis. By E. Raymond Hall and Walter W. Dalquest. Pp.
581-590, 5 figures in text. January 20, 1950.

26. A synopsis of the American bats of the genus
Pipistrellus. By E. Raymond Hall and Walter W. Dalquest. Pp.
591-602, 1 figure in text. January 20, 1950.

Index pp. 605-638.

The Pocket Gophers (Genus Thomomys) of Utah

BY

STEPHEN D. DURRANT

University of Kansas Publications Museum of Natural History

Volume 1, No. 1, pp. 1-82, 1 figure in text August 15, 1946

UNIVERSITY OF KANSAS LAWRENCE 1946

The Pocket Gophers (Genus Thomomys) of Utah

BY

STEPHEN D. DURRANT

University of Kansas Publications Museum of Natural History

Volume 1, No. 1, pp. 1-82, 1 figure in text August 15, 1946

UNIVERSITY OF KANSAS LAWRENCE 1946

UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY

Editors: E. Raymond Hall, Chairman, Donald S. Farner, Donald F. Hoffmeister

Volume 1, No. 1, pp. 1-82, 1 figure in text.

Published AUGUST 15, 1946

UNIVERSITY OF KANSAS Lawrence, Kansas

PRINTED BY FERD VOILAND, JR., STATE PRINTER TOPEKA, KANSAS 1946

21-2786

The Pocket Gophers (Genus Thomomys) of Utah

By

STEPHEN D. DURRANT

Contribution from the Department of Biology, University of Utah, and the Museum of Natural History, University of Kansas.

INTRODUCTION

The history of pocket gophers of Utah begins with J. A. Allen's mention in 1874 of mounds of these animals. For them he employed the name "_Thomomys rufescens?_" (1874:65). Actual specimens were reported upon a year later by Elliot Coues (1875:251, 256), who used the name _Thomomys talpoides_ for specimens from "Utah" but later in the same paper listed specimens from Provo as _Thomomys talpoides bulbivorus_. Even as the great variation in Utah pocket gophers has been perplexing to modern workers, so it was also to Coues seventy years ago who left the problem with the statement that animals from Provo "exhibit among themselves such variations that their labelling becomes a matter of indifference"! In the same year in another report, Coues and Yarrow (1875:112) used the name _Thomomys talpoides umbrinus_ for animals from Provo. In 1877, Coues again referred these same animals to _Thomomys talpoides bulbivorus_, using the name _umbrinus_ for the animals of only southern Utah (Coues, 1877:627, 628). The two names _Thomomys bottae_ and _Thomomys talpoides_, now applicable to gophers in Utah, were synonomized under the name _Thomomys talpoides bulbivorus_ by Coues (1875:256; 1877:627). After this beginning only three other papers, all by J. A. Allen, appeared in the next twenty years. They were reports on collections of mammals made by Walter W. Granger and Charles P. Rowley. One of these contained the description of _Thomomys aureus_. Likewise, in the ensuing twenty years there were only three papers, one in 1901 by C. Hart Merriam in which he described _Thomomys uinta_, one by Allen (1905:119), and Vernon Bailey's (1915) "Revision of the pocket gophers of the genus _Thomomys_" in which he summarized the information then available on these animals within the state. Barnes (1922 and 1927) reprinted the information summarized by Bailey. Since 1927 approximately twenty-five papers, mostly taxonomic, have been published in which reference is made to Utah gophers, and especially since 1930 much information has been accumulated about the distribution and speciation of this genus within the state.

Specimens to the number of 1,045 have been available for this study. Whereas Bailey (_loc. cit._) listed only four kinds belonging to four different species, thirty-five kinds are now known from Utah. Seven of these are herein described as new. The thirty-five kinds are found to belong to only two instead of four full species.

Inasmuch as the literature is scattered and since names have been applied in different ways at different times, I have attempted to give a synonomy as complete as possible for each form found within the state.

The bibliographies of Hayward (1936 and 1941) and Miller's (1924) "List of North American mammals" have been of great use.

Capitalized color terms in the accounts are after Ridgway, Color Standards and Color Nomenclature, Washington, D. C., 1912.

In the lists of specimens examined, the localities are listed by counties from west to east, beginning at the northwestern corner of the state, and within each county from north to south. When two localities are on the same latitude, the westernmost is listed first.

I am deeply indebted to Professor R. V. Chamberlin, of the
University of Utah, for encouragement and support in my
investigation. I also acknowledge critical assistance in the
preparation of this paper from Professor E. Raymond Hall of
the University of Kansas. For the loan of specimens I am
grateful to the following: Clinton G. Abbott and Lawrence M.
Huey, Natural History Museum of San Diego, San Diego,
California; Harold E. Anthony and J. Eric Hill, American
Museum of Natural History, New York City, New York; Seth B.
Benson, Museum of Vertebrate Zooelogy, University of
California, Berkeley, California; William H. Burt, Museum of
Zooelogy, University of Michigan, Ann Arbor, Michigan; J.
Kenneth Doutt, Carnegie Museum, Pittsburgh, Pennsylvania;
Ross Hardy, Dixie Junior College, St. George, Utah; C. Lynn
Hayward and Vasco M. Tanner, Brigham Young University,
Provo, Utah; H. H. T. Jackson and Viola S. Schantz, United
States Fish and Wildlife Service, U. S. National Museum,
Washington, D. C.; Remington Kellogg and Alexander Wetmore,
U. S. National Museum, Washington, D. C.; J. S. Stanford,
Utah State Agricultural College, Logan, Utah.

Unless otherwise indicated, specimens are in the Museum of
Zooelogy, University of Utah, Salt Lake City, Utah. In lists
of specimens examined, abbreviations are employed as
follows:

(A. M. N. H.) American Museum of Natural History. (N. H. M. S. D.) Natural History Museum of San Diego. (M. V. Z.) Museum of Vertebrate Zooelogy, University of California. (U. M.) Museum of Zooelogy, University of Michigan. (C. M.) Carnegie Museum. (R. H.) Collection of Ross Hardy. (B. Y. U.) Brigham Young University. (U. S. N. M.) United States National Museum. (U. S. A. C.) Utah State Agricultural College. (K. U.) Museum of Natural History, University of Kansas.

Guide to subspecies:

1. _T. t. gracilis_
2. _T. t. wasatchensis_
3. _T. t. oquirrhensis_
4. _T. t. uinta_
5. _T. t. pygmaeus_
6. _T. t. ravus_
7. _T. t. ocius_
8. _T. t. moorei_
9. _T. t. fossor_
10. _T. t. parowanensis_
11. _T. t. levis_
12. _T. b. aureiventris_
13. _T. b. robustus_
14. _T. b. minimus_
15. _T. b. nesophilus_
16. _T. b. stansburyi_
17. _T. b. albicaudatus_
18. _T. b. bonnevillei_
19. _T. b. centralis_
20. _T. b. sevieri_
21. _T. b. convexus_
22. _T. b. tivius_
23. _T. b. contractus_
24. _T. b. lenis_
25. _T. b. levidensis_
26. _T. b. osgoodi_
27. _T. b. howelli_
28. _T. b. wahwahensis_
29. _T. b. dissimilis_
30. _T. b. aureus_
31. _T. b. birdseyei_
32. _T. b. virgineus_
33. _T. b. planirostris_
34. _T. b. absonus_
35. _T. b. alexandrae_

GENUS =Thomomys= Wied

All pocket gophers of Utah belong to the genus _Thomomys_. There are only two species within the state, _Thomomys bottae_ with twenty-four subspecies and _Thomomys talpoides_ with eleven subspecies.

Due to marked mutational capacities and ready response to environmental pressures and sedentary habits, pocket gophers differentiate readily into numerous subspecies. It is well known that Utah by its highly varied topography and climate possesses widely different types of habitats. The aforementioned plasticity of these animals and possibly the fact that both species are at the extreme limits of their ranges in Utah account for the numerous forms found within the state.

The genus may be characterized as follows: Highly specialized fossorial rodents, with heavy, thick bodies; all four legs of approximately equal length, but front legs more muscular for digging, and feet provided with long claws; external fur-lined cheek pouches; small eyes, short ears and tail; upper incisors long and projecting external to lips. Skull: Stout and flattened; zygomatic arches well developed and usually widely spreading; all teeth with permanent pulp cavities; incisors superficially smooth, but fine median groove present on anterior face of each upper incisor; dental formula, i. 1/1, c. 0/0, p. 1/1, m. 3/3; external auditory canal long; stapedial artery small and enclosed within an osseous canal.

=Thomomys talpoides= (Richardson)

_Thomomys talpoides_ is a northern species that in Utah approaches the southern limits of its range. The animals of this species inhabit the mountains and high valleys. In the southward extension of their range, as in Utah, they are found at higher elevations which zonally represent lower elevations at more northern latitudes. The specific characters are: Sphenorbital fissure absent; incisive foramina anterior to infraorbital canal; anterior prism of P4 triangular; interparietal relatively large; lambdoidal suture concave posteriorly in region of interparietal, in Utah specimens.

=Thomomys talpoides gracilis= Durrant

_Thomomys quadratus gracilis_ Durrant, Bull. Univ. Utah, 39
(No. 6):3, February 28, 1939.

_Thomomys talpoides gracilis_ Durrant, Bull. Univ. Utah, 30
(No. 5):6, August 24, 1939; Goldman, Journ. Mamm., 25:414,
December 12, 1944.

_Thomomys quadratus fisheri_ Hall, Univ. California Publ.
Zooel., 37:4, April 10, 1931.

_Thomomys uinta_ Bailey, N. Amer. Fauna, 39:114, November
15, 1915; Barnes, Bull. Univ. Utah, 12 (No. 15):83, April,
1922; Bull. Univ. Utah, 17 (No. 12):104, June, 1927.

_Type._--Male adult, skin and skull; No. 44866, Museum of Vertebrate Zooelogy, University of California; Pine Canyon, 6,600 ft., 17 mi. NW Kelton, Box Elder County, Utah; July 12, 1930; collected by Annie M. Alexander; original number 676.

_Range._--Mountainous regions of extreme northwestern Utah.

_Diagnosis._--Size medium (see measurements). Color: Upper parts Buckthorn Brown grading over the sides and flanks to Light Buff on the underparts; chin white; nose and postauricular patches grayish black. Claws on front feet long and slender. Skull: Long and slender; rostrum long and narrow; zygomatic and mastoidal breadths slight; palatal pits deep; upper incisors narrow; basioccipital wide.

_Comparisons._--Compared with topotypes of _Thomomys talpoides fisheri_, _gracilis_ is of approximately the same size. Upper parts darker and underparts lighter; postauricular patches larger and darker; claws on front feet longer and slenderer. Skull: Generally longer and narrower; nasals and rostrum longer; basioccipital wider.

As compared with _T. t. uinta_, _gracilis_ is of approximately the same size but differs as follows: Color: Lighter throughout; postauricular patches markedly smaller and lighter; inguinal and pectoral regions much lighter. One characteristic difference is in the ear. In _uinta_ the external opening of the ear is much larger; the pinna of the ear is larger, more rounded at the tip, and lacks most of the pigmentation on the inner margin. Skull: Generally narrower and longer; nasals longer; zygomatic arches weaker and less angular; upper incisors narrower.

This form is easily distinguished from _bridgeri_ by smaller size, and by the skull being longer, narrower and less angular.

From _Thomomys talpoides oquirrhensis_ to the southeast, _T. t. gracilis_ can be distinguished by: Total length and ear shorter. Color: Generally lighter, except the underparts which are about the same; postauricular patches larger and more deeply pigmented. Skull: Braincase less inflated; nasals truncated posteriorly as opposed to rounded; zygomatic and mastoidal breadths less; rostrum shorter but narrower; upper incisors narrower and shorter.

For comparisons with _wasatchensis_ see comparisons under that form.

In general, this mountain form can be distinguished from all other _talpoides_ in Utah by lighter color, narrow, slender, "graceful" skull whence the name _gracilis_ is derived.

_Remarks._--In Utah, _gracilis_ is limited to the extreme northwestern corner of the state. This part of the state is in the Snake River drainage. The main part of the range of this race lies in south-central and southwestern Idaho and northeastern Nevada. The center of its range might be considered to be in the Jarbidge Mountains area of Nevada. The south slopes of these mountains are in the Humboldt River drainage, while the north slopes are in the Snake River drainage, and this subspecies occurs as far north as the Snake River and south and west almost to central Nevada. No specimens are available from the area in Utah between the Raft River Mountains inhabited by _gracilis_ and the Wasatch Mountains in central Utah inhabited by _wasatchensis_. Judging from the nature of the terrain, the range of _gracilis_ does not extend eastward much beyond the Raft River Mountains. The type locality for a gopher of a different species, _Thomomys bottae aureiventris_, is in the first valley east of these mountains. Furthermore, all valleys to the east and south, as far as known, are inhabited by gophers of the _bottae_ group. Also, all mountain ranges in this area, as far east as the Wasatch Mountains are inhabited by members of the _bottae_ group.

No specimens from Utah indicate intergradation between _gracilis_ and _wasatchensis_, the form to the east, but specimens from farther north at Albion, Cassia County, Idaho, do show intergradation. Bailey (1915:116), Hall (1931:4), and Durrant (1939:6) have reported on these specimens which at the present time seem best referred to _T. t. gracilis_.

_Specimens examined._--Total, 24, distributed as follows:
_Box Elder County_: Yost, 4 (U. S. A. C.); Pine Canyon,
6,600 ft., 17 mi. NW Kelton, 7 (M. V. Z.): Lynn Canyon, Raft
River, 4; Park Valley, 3 (U. S. A. C.); Etna, 4 (U. S. A.
C.); Raft River Mountains, Clear Creek Camp of Minnedoka
National Forest, 1 (R. H.); Raft River Mountains, 1,500 feet
above Clear Creek Camp of Minnedoka National Forest, 1 (R. H.).

=Thomomys talpoides wasatchensis= new subspecies

_Thomomys quadratus uinta_ Hall, Univ. California Publ.
Zooel., 37:4, April 10, 1931.

_Thomomys talpoides uinta_ Goldman, Journ. Mamm., 20:234.
May 14, 1939.

_Thomomys uinta_ Bailey, N. Amer. Fauna, 39:114, November
15, 1915; Barnes, Bull. Univ. Utah, 12 (No. 15):83, April,
1922; Bull. Univ. Utah, 17 (No. 12):104, June, 1927;
Stanford, Journ. Mamm., 12:360, November 11, 1931.

_Type._--Male, adult, skin and skull, No. 1604, Museum of Zooelogy, University of Utah; Midway, 5,500 ft., Wasatch County, Utah; September 1, 1936; collected by S. D. Durrant; original number 1049.

_Range._--Wasatch Mountains and neighboring high valleys as far south as Spanish Fork Canyon, Utah County.

_Diagnosis._--Size medium (see measurements). Color: Upper parts Snuff Brown, finely mixed with black; sides and flanks Sayal Brown; underparts overlaid with Cinnamon Buff, with suffusion of black on underfur; postauricular patches black, extending around ear; ears pointed and covered with black hairs; nose, cheeks, chin and top of head dusky; front feet, hind feet and distal part of tail white; tail covered proximally with light brown hairs. Skull: Moderately heavy and ridged; nasals long, wide posteriorly and not markedly dilated distally; posterior ends of nasals emarginate; zygomatic arches fairly widely spreading and angular, being nearly straight in adults, but tending to bow out slightly at posterior ends in young; zygomatic processes of maxillae heavy; interparietal small and variously shaped, but always wider than long; interorbital region fairly wide; well marked dorsal depression in frontals posterior to ends of nasals; interpterygoid space narrowly V-shaped; tympanic bullae large; occipital condyles large and widely separated; foramen magnum large and higher than wide; basioccipital wide; dentition light.

_Comparisons._--From topotypes of _Thomomys talpoides moorei_, _wasatchensis_ differs as follows: Size slightly larger; ears longer and more pointed. Color: Generally darker throughout; postauricular patches smaller. Skull: Zygomatic arches not as widely spreading; zygomatic processes of squamosals dip farther ventrally; premaxillae less extended posterior to nasals; nasals wider posteriorly and less dilated distally; median dorsal depression of frontals present; tympanic bullae generally larger, but less inflated ventrally; foramen magnum larger especially in dorsoventral dimension; occipital condyles farther apart; basioccipital wider; alveolar length of upper molar series less; molariform teeth smaller; upper incisors wider and shorter.

Topotypes of _wasatchensis_ differ from topotypes and near topotypes of _Thomomys talpoides uinta_ as follows: Size larger in every measurement taken. Color: Darker throughout; ears longer and more pigmented; opening of external ear smaller; postauricular patches larger. Skull: In females larger throughout, more massive and angular; nasals longer, wider and not so dilated distally; rostrum longer but wider; zygomatic arches wider, more angular and less widely spreading posteriorly; extension of premaxillae posterior to nasals less; tympanic bullae larger, but less inflated ventrally; foramen magnum larger and more ovoid; width across occipital condyles greater; basioccipital wider; molariform teeth smaller; upper incisors shorter and wider.

Topotypes of _wasatchensis_ can be distinguished from those of _Thomomys talpoides oquirrhensis_ as follows: Size larger; tail longer; ears longer. Color: Slightly darker on sides and underparts. Skull: Heavier, more ridged and angular; nasals more dilated distally; posterior ends of nasals more deeply emarginate; zygomatic arches heavier and more widely spreading, but more nearly parallel and less divergent posteriorly; zygomatic processes of maxillae much heavier; braincase and tympanic bullae larger; pterygoid hamulae shorter; interpterygoid space more narrowly V-shaped; wider across occipital condyles; foramen magnum larger and more ovoid.

From topotypes of _Thomomys talpoides gracilis_, _wasatchensis_ differs as follows: Size larger; hind foot longer; ears longer and more pointed. Color: Darker throughout; postauricular patches relatively smaller. Skull: Larger, heavier and more angular; nasals emarginate posteriorly as opposed to truncate; rostrum heavier; zygomatic arches heavier and more widely spreading; zygomatic processes of maxillae much heavier and more angular; mastoid breadth greater; interparietal relatively smaller; extension of premaxillae posterior to nasals actually as well as relatively less; palatal pits deeper; tympanic bullae larger; interpterygoid space more narrowly V-shaped; foramen magnum more ovoid; upper incisors wider.

Topotypes of _wasatchensis_ can be readily distinguished from those of _Thomomys talpoides levis_ and _parowanensis_ by larger size; more massive, ridged, angular skulls; larger tympanic bullae; large, ovoid foramen magnum; and relatively smaller interparietal.

_Remarks._--Specimens from Mount Timpanogos and environs are intergrades between _moorei_ and _wasatchensis_. They resemble _moorei_ in the shape and size of the tympanic bullae, and are intermediate in the size and shape of the foramen magnum. In the majority of characters they resemble _wasatchensis_ to which they are here referred. The animals from east of Salt Lake City in Salt Lake County are intergrades between _oquirrhensis_ and _wasatchensis_ and show some characters of _uinta_, but are referable to _wasatchensis_. Animals from Morgan County and western Summit County are intergrades between _wasatchensis_ and _uinta_. They resemble _uinta_ in size, shape of nasals and size of tympanic bullae. The remainder of the cranial details place them with _wasatchensis_. Morphologically the animals from Wellsville, Cache County, were the closest to the topotypes of any obtained and are nearly indistinguishable from them. Like the topotypes of _wasatchensis_ this population inhabits a high valley. The remaining specimens from Cache County resemble those from Morgan and Summit counties.

_Specimens examined._--Total, 119, distributed as follows:
_Cache County_: Logan Canyon, Beaver Basin, Utah-Idaho Line,
2 (U. S. A. C); Logan Canyon, Tony Grove Camp, 6 (U. S. A.
C); Logan Canyon, Green Camp, 3 (U. S. A. C); Logan Canyon,
3 (U. S. A. C); Logan Mountains, 20 mi. E Logan, 3 (U. S. A.
C); Logan Peak area, 13 (U. S. A. C); near Providence Peak,
Logan Mountains, 1 (U. S. A. C.); Wellsville, 10 (U. S. A.
C); Hardware Ranch, Blacksmith Fork, 1 (U. S. A. C); Avon, 1
(U. S. A. C); 1 mi. E Avon, 1 (U. S. A. C); 7-8 mi. E Avon,
1 (U. S. A. C). _Weber County_: South Fork, Ogden River, 18
mi. E Ogden, 4 (M. V. Z.). _Morgan County_: East Canyon, 18
mi. NW Park City, 6,000 ft., 1. _Davis County_: 8 mi. NE
Salt Lake City, 1. _Salt Lake County_: Mouth of Dry Canyon,
1 mi. NE Salt Lake City, 1; 4 mi. above mouth City Creek
Canyon, 5,000 ft., 1; mouth of Emigration Canyon, 1; mouth
of Millcreek Canyon, 1; Lambs Canyon, 13 mi. SE Salt Lake
City, 2 (C. M.); mouth of Big Cottonwood Canyon, 1. _Summit
County_: Park City, 1 (U. S. N. M.). _Wasatch County_:
Midway, 5,500 ft., 29. _Utah County_: Mt. Timpanogos, 1 mi.
N Aspen Grove, 7,500 ft., 20; Aspen Grove, Mt. Timpanogos, 5
(1, U. S. A. C.; 4, B. Y. U.); Head of Grove Creek, Mt.
Timpanogos, 4 (B. Y. U.).

_Additional Records_: _Weber County_: Ogden, 6. _Salt Lake
County_: Parleys Canyon, 1 (Bailey, 1915:114).

=Thomomys talpoides oquirrhensis= Durrant

_Thomomys talpoides oquirrhensis_ Durrant, Bull. Univ. Utah,
30 (No. 5):3, October 24, 1939.

_Type._--Male, adult, skin and skull; No. 2605, Museum of Zooelogy, University of Utah; Settlement Creek, Oquirrh Mountains, 6,500 ft., Tooele County, Utah; June 11, 1938; collected by S. D. Durrant; original number 1461.

_Range._--Known only from the Oquirrh Mountains, which are in Salt Lake, Tooele and Utah counties, Utah.

_Diagnosis._--Size medium (see measurements); ear long; tail short, claws of front feet long and slender. Color: Upper parts Buckthorn Brown, mixed with black, grading over the sides and flanks to Pinkish Buff on the ventral surface; feet white; nose grayish black; postauricular patches medium in size and black; chin and throat with varying amounts of white; proximal two-thirds of tail dark brown, distal third white. Skull: Long and slender, but relatively wide across mastoidal region; nasals long and rounded posteriorly; rostrum long and narrow; zygomatic arches weak and not widely spreading, tending to be slightly bowed out posteriorly, but in the main roughly parallel to the sides of the skull; outer margin of zygomatic arch slightly concave, and zygomatic arch dips deeply ventrad; dorsal surface of skull smooth, with weakly defined parietal crests; parietal crest nearly parallel, but bowed medially, in parietal region, and flaring widely posteriorly to pass lateral to interparietal; tympanic bullae large, truncate anteriorly and markedly inflated ventrally; upper incisors short and fairly robust.

_Comparisons._--From _Thomomys talpoides uinta_, _oquirrhensis_ may be differentiated as follows: Color: Darker throughout; postauricular patches larger and darker; ears longer and more pointed; inner margin of pinna heavily pigmented; external opening of ear smaller. Skull: Nasals rounded posteriorly rather than deeply emarginate, and less flaring distally; zygomatic arches weaker and markedly less widely spreading; pterygoid hamulae weaker; basisphenoid narrower; upper incisors shorter and wider.

For comparisons between _oquirrhensis_ and _Thomomys talpoides gracilis_, and _oquirrhensis_ and _wasatchensis_, see comparisons under those forms.

Topotypical specimens of _oquirrhensis_ can be distinguished from those of _Thomomys talpoides moorei_ as follows: Color generally darker, due to greater admixture of black; terminal bands of hair actually lighter; postauricular patches larger and darker; ears longer, more pointed and with more heavily pigmented pinnae; tail shorter. Skull: About the same size; smoother; zygomatic arches weaker and less widely spreading; nasals rounded posteriorly as opposed to emarginate; mastoid breadth less; pterygoid hamulae weaker; upper incisors wider.

_Remarks._--This race is limited to the Oquirrh Mountains, a high mountain range that lies parallel to, and just west of the Wasatch Mountains, in Utah, Salt Lake and Tooele counties. These mountains were connected in past times to the Wasatch Mountains by the Transverse Range, and by a sand and gravel bar deposited by Pleistocene Lake Bonneville. The Jordan River in its course from Utah Lake to the Great Salt Lake has cut a channel through the aforementioned bar. This channel has been cut to the level of the surrounding valleys as is indicated by the meandering nature of the stream through this part of its course. As a result the Oquirrh Mountains are relatively isolated. Although separated from the Wasatch Mountains by the Jordan River Valley only a few miles wide, the pocket gophers are distinct on each mountain. A population of _T. bottae_ is interposed between the two mountain ranges as is indicated by specimens from Riverton, six miles north of the Transverse Range. The populations of _bottae_ are subspecifically the same on the two sides of the Jordan River.

On the east side of the Oquirrh Mountains, pocket gophers collected from the Jordan Valley up Rose Canyon to about 5,000 feet elevation were all of the species _T. bottae_. Between 5,000 and 6,000 feet there is an area in which the ranges of _bottae_ and _talpoides_ overlap. When trapping, it is possible to predict what species will be taken by the types of burrows and soil. Gophers of the _bottae_ group have their burrows in the areas of the deepest soil and heaviest vegetation, whereas the areas of shallow, rocky soil covered with sparse vegetation are the habitat of _talpoides_. Above 6,000 feet the only gopher encountered is _talpoides_. Along Settlement Creek on the west side of the Oquirrh Mountains, which is the type locality of _oquirrhensis_, _bottae_ and _talpoides_ have essentially the same vertical distribution as in Rose Canyon. On this mountain the two species appear to be in competition.

The available information, based on collections, indicates that the Oquirrh Mountains are the only mountains west of the Wasatch Range upon which _talpoides_ occurs. In Utah, all other mountains to the west, as far as known, are inhabited by subspecies of of _Thomomys bottae_.

_Specimens examined._--Total, 41, as follows: _Tooele
County_: Settlement Creek, Oquirrh Mountains, 6,500 ft., 14.
_Salt Lake County_: Rose Canyon, Oquirrh Mountains, 5,650
ft., 27.

=Thomomys talpoides uinta= Merriam

_Thomomys uinta_ Merriam, Proc. Biol. Soc. Washington,
14:112, July 19, 1901; Bailey, N. Amer. Fauna, 39:113,
November 15, 1915; Barnes, Bull. Univ. Utah, 12 (No. 15):83,
April, 1922; Bull. Univ. Utah, 17 (No. 12):104, June, 1927;
Stanford, Journ. Mamm., 12:360; November 11, 1931; Goldman,
Journ. Washington Acad. Sci., 28:333, July 15, 1938; Davis,
The Recent mammals of Idaho, pp. 239, 259, The Caxton
Printers, Ltd., Caldwell, Idaho, April 5, 1939.

_Thomomys talpoides uinta_ Goldman, Journ. Mamm., 20:234,
May 14, 1939.

_Thomomys quadratus uinta Hall_, Univ. California Publ.
Zooel., 37:4, April 10, 1931.

_Type._--Male, adult, skin and skull, No. 22501/30051, U. S. National Museum (Biological Surveys Collection); north base Gilbert Peak, Uinta Mountains, 10,000 ft., Summit County, Utah; June 6, 1890; collected by Vernon Bailey; original number 1262 (after Merriam, type not seen).

_Range._--Uinta Mountains in Duchesne County, eastern Wasatch and Summit counties, and western Uintah County south to the Roan, Brown and Book cliffs in Carbon County.

_Diagnosis._--Size medium (see measurements). Color: Upper parts Snuff Brown finely mixed with black, paling over sides and flanks to near Pinkish Buff on underparts; postauricular patches relatively small and dusky; external opening of ear large; pinnae usually lightly pigmented; hind feet white; front feet usually white only at base of toes; distal third to half of tail white; tail usually light below, with proximal dorsal half covered with darker hairs; nose, chin, cheeks and top of head dusky; usually considerable white on throat. Skull: Small, slender, and not heavily ridged; nasals short and dilated distally; posterior margins of nasals emarginate; zygomatic arches moderately widely spreading, widest posteriorly; interparietal pentagonal or subquadrangular; interpterygoid space V-shaped; tympanic bullae well inflated ventrally; upper incisors long and narrow.

_Comparisons._--For comparisons with other subspecies of _Thomomys talpoides_, see accounts of those forms.

_Remarks._--The range formerly ascribed to _uinta_ (Bailey, 1915:114; Barnes, 1922:83, 1927:104) is now known to be inhabited by animals belonging to three distinct subspecies. The range of _uinta_ as now understood is restricted to the southern and western parts of the Uinta Mountains and their environs. Three specimens from the Book Cliffs, Sunnyside, Carbon County, are not typical, but in a majority of their characters agree with _uinta_ to which they are here referred.

I have seen only one specimen from the type locality. It is one of the series on which Merriam (1901:112) based his original description. In addition, I have studied several large series of near topotypes. From the material at hand, and from Merriam's description (_loc. cit._), I regard the animals on which the name _uinta_ was based as intergrades between _Thomomys talpoides ravus_, the race to the northeast, on the one hand and the animals of the western and southern parts of the Uinta Mountains on the other hand. The affinities of the type series are with the animals from the latter area which are here all referred to _uinta_.

_Specimens examined._--Total, 41, distributed as follows:
_Summit County_: 2 mi. S junction Bear River and Haydens
Fork, 2 (C. M.); N base, Gilbert Peak, 10,000 ft., 1 (U. S.
N. M.); Smith and Moorehouse Creek, 2; Bald Peak, 25 mi. NE
Kamas, 15 (8, M. V. Z.; 6, C. M.). _Duchesne County_: Petty
Mountain, 15 mi. N Mountain Home, 9,500 ft., 6 (C. M.).
_Wasatch County_: Wolf Creek Pass, 18 mi. NW Hanna, 1 (U. S.
A. C.); Lost Lake, Uinta Mountains, 10 (B. Y. U.); Current
Creek, Uinta Mountains, 1 (U. S. N. M.). _Carbon County_:
Forks, Sunnyside, 9,000 ft., 3.

_Additional records._--_Summit County_: Uinta Mountains, 6
(see Bailey, 1915:114).

=Thomomys talpoides pygmaeus= Merriam

_Thomomys pygmaeus_ Merriam, Proc. Biol. Soc. Washington,
14:115. July 19, 1901.

_Thomomys talpoides pygmaeus_ Davis, The Recent mammals of
Idaho, p. 252, The Caxton Printers, Ltd., Caldwell, Idaho,
April 5, 1939.

_Type._--Male, adult, skin and skull, No. 55251, U. S. National Museum (Biological Surveys Collection); 10 mi. NE Montpelier, in open sagebrush of Transition Zone, 6,600 ft., Bear County, Idaho; July 29, 1893; collected by Vernon Bailey: original number 4150 (after Merriam, type not seen: see, also, Bailey, 1915:109).

_Range._--Limited to Daggett County.

_Diagnosis._--Size: Small (see measurements). Color: Upper parts near Bister slightly mixed with black, grading over sides and flanks to Ochraceous Buff on underparts; postauricular patches small and dusky; hind feet white; front feet dusky, being white only at base of claws; chin and nose dusky; tail brown, lighter below and tipped with white. Skull: Very small, slender and smooth; nasals short and slender; zygomatic arches weak and not widely spreading; rostrum narrow; extension of premaxillae posterior to nasals short; parietal ridges hardly noticeable; interparietal large; extension of supraoccipital posterior to lambdoidal suture long; tympanic bullae actually small, but relatively large; basioccipital narrow; interpterygoid space narrow and acutely angled; upper incisors markedly recurved; molariform teeth relatively large.

_Comparisons._--This small pocket gopher can be distinguished from all other members of _Thomomys talpoides_ occurring in Utah by remarkably small size, and slender, weak, small skull with strongly recurved upper incisors.

_Remarks._--The specimens used in this study were those recorded by Svihla (1931:261). She reports that they were obtained in the flood-plain banks of the streamsides, and preferred the pine belt. This shows probably an extension of range with reference to life zones, as heretofore the main reported localities of capture have been in sagebrush in the Transition Life-zone.

Insofar as I am aware, Mrs. Svihla's specimens are the only ones of this subspecies ever obtained in Utah. Additional work is necessary in southwestern Wyoming to outline accurately the geographic distribution of this subspecies. In comparison with topotypes, the specimens from Utah are lighter in color and some specimens have slightly larger skulls, suggesting slight intergradation with _Thomomys talpoides uinta_.

_Specimens examined._--Total, 18 (all in Museum of Zooelogy,
University of Michigan), distributed as follows: _Daggett
County_: Sheep Creek, 4; 1 mi. W Summit Springs, 4; Beaver
Creek, 22 mi. S Manila, 9; Granite Park, 24 mi. S Manila, 1.

=Thomomys talpoides ravus= new subspecies

_Type._--Male, adult, skin and skull, No. 13690, Carnegie Museum; Vernal-Manila Highway, 19 mi. N Vernal, 8,000 ft., Uintah County, Utah; August 22, 1937; collected by J. K. and M. T. Doutt; original number 4718.

_Range._--Uinta Mountains in Daggett, northern Uintah and northern Summit counties.

_Diagnosis._--Size large (see measurements); ears relatively narrow; hind foot relatively small. Color: Upper parts between Drab and Light Drab, darkest along middorsal line due to mixture of hairs tipped with light brown; sides and flanks Light Drab; entire underparts creamy white; front and hind feet, ventral surface of tail and end of tail white; proximal two-thirds of tail covered dorsally with light brown hairs; nose and cheeks dusky; postauricular patches black. Skull: Large, heavy and ridged; rostrum long and narrow; nasals long, moderately dilated distally and with a distal hump; posterior ends of nasals emarginate; parietal and lambdoidal crests well developed; zygomatic arches moderately heavy and widely spreading, widest posteriorly; zygomatic processes of maxillae moderately heavy and flaring abruptly from base of rostrum; marked middorsal depression in frontals present; interparietal pentagonal; extension of premaxillae posterior to nasals long; posterior tongues of premaxillae long, slender and rounded proximally; braincase high, vaulted and relatively narrow; tympanic bullae well inflated ventrally, and ridged in old animals; pterygoid hamulae long; interpterygoid space narrowly V-shaped; upper incisors long and narrow; molariform teeth medium.

_Comparisons._--Compared with topotypes of _Thomomys talpoides bridgeri_, _ravus_ differs as follows: Size larger; hind foot smaller; ears narrower. Color: Lighter throughout, grayish as opposed to brown. Skull: Smaller, narrower, less angular and less massive; nasals, rostrum, zygomatic processes of maxillae, ascending branches of premaxillae and posterior tongues of premaxillae all narrower; extension of premaxillae posterior to nasals longer; interparietal wider; braincase higher and narrower; tympanic bullae approximately the same size, but more inflated ventrally; interpterygoid space more narrowly V-shaped; upper incisors narrower; molariform teeth weaker.

Compared with topotypes and near topotypes of _Thomomys talpoides uinta_, _ravus_ differs as follows: Size larger in every measurement taken. Color: Lighter throughout, being grayish as opposed to brown. Skull: Larger in every measurement taken; rostrum and nasals actually as well as relatively longer; extension of premaxillae posterior to nasals longer; upper incisors longer and wider; molariform teeth larger.

There is only one other gray subspecies of _Thomomys talpoides_ in Utah, _Thomomys talpoides ocius_. Topotypes of _ravus_ differ from it as follows: Size markedly larger in every measurement taken. Color: Darker, more brown hairs. Skull: Larger in every measurement taken; premaxillae extended farther posteriorly to nasals; extension of supraoccipital posterior to lambdoidal suture markedly less; tympanic bullae actually as well as relatively smaller; upper incisors longer and more procumbent.

This new subspecies can be readily distinguished from all other subspecies of _Thomomys talpoides_ occurring in Utah by markedly greater size and paler, more grayish color.

_Remarks._--The range of this form appears to be limited to the north slopes of the Uinta Mountains, except in Daggett County where it occurs also on the south slopes. Intergradation in color and in cranial details with _bridgeri_ is shown by animals from the East Fork of Blacks Fork, thirty-one miles SSW Fort Bridger, and by those from Henrys Fork, 8,300 ft., both in Summit County. Due to the grayish color and the narrower, weaker skull they are referred to _ravus_. Intergradation with _uinta_ is shown by specimens from the type locality of the latter race. The type series of _uinta_ consists of intergrades between _ravus_ and the animals to the west and south (see remarks under _uinta_).

It is doubtful whether _bridgeri_ occurs in Utah. Material from Rich County and extreme northern Cache County would settle the question. Perhaps _bridgeri_ is restricted to the lower valleys in southwestern Wyoming. Two specimens from northern Cache County, from Logan Canyon, Beaver Basin, Utah-Idaho Line appear to be intergrades between _bridgeri_ and _wasatchensis_, but are referable to the latter race.

_Specimens examined._--Total, 38, distributed as follows:
_Summit County_: Henrys Fork, 8,300 ft., 8; E Fork, Blacks
Fork, 31 mi. SSW Fort Bridger, 4 (C. M.). _Daggett County_:
Vernal-Manila Road, 4 mi. W Green's Lake, 7,500 ft., 6 (C.
M.); Elk Park, Uinta Mountains, 5 (B. Y. U.). _Uintah
County_: Trout Creek, SE Trout Peak, 22 mi. NW Vernal, 9,300
ft., 5 (C. M.); Vernal-Manila Highway, 19 mi. N Vernal,
8,000 ft., 6 (C. M.); Taylor Peak, 17 mi. N Vernal, 4 (C.
M.).

=Thomomys talpoides ocius= Merriam

_Thomomys clusius ocius_ Merriam, Proc. Biol. Soc.
Washington, 14:114, July 19, 1901.

_Thomomys clusius_ Allen, Bull. Amer. Mus. Nat. Hist.,
13:246, November 25, 1896.

_Thomomys ocius_ Bailey, N. Amer. Fauna, 39:107, November
15, 1915; Barnes, Bull. Univ. Utah, 12 (No. 15):83, April,
1922; Bull. Univ. Utah, 17 (No. 12):102, June, 1927.

_Type._--Male, adult, skin and skull, No. 18852/25586, U. S. National Museum (Biological Surveys Collection); dry sagebrush mesas at Harveys Ranch, Smiths Fork, 6 mi. SW Fort Bridger, 6,657 ft., Uinta County, Wyoming; May 24, 1890; collected by Vernon Bailey; original number 1194 (after Bailey, type not seen).

_Diagnosis._--Size small (see measurements). Color: Upper parts Tilleul Buff overlaid with Avellaneous, grading over sides and flanks to nearly white on underparts; underparts with faint wash of creamy white; postauricular patches small and dusky and completely circling the ear; nose and cheeks dusky; front feet, hind feet, throat, ventral surface of tail and distal half of tail white. Skull: Small, slender but compact; nasals rounded posteriorly; extension of premaxillae posterior to nasals very short; zygomatic arches robust, but not widely spreading, widest posteriorly; interparietal large and pentagonal in shape; extension of supraoccipital posterior to lambdoidal suture long; tympanic bullae actually as well as relatively large; basioccipital narrow; pterygoid hamulae long and ridged; upper incisors short and strongly recurved.

_Comparisons._--Compared with one topotype and seven near topotypes of _Thomomys talpoides pygmaeus_, _ocius_ differs as follows: Size larger in every measurement taken. Color: Lighter throughout, grayish as opposed to brown; distal half of tail white as opposed to only a few white hairs at tip of tail. Skull: Larger in every measurement taken; skull more compact; zygomatic arches heavier and more widely spreading posteriorly; tympanic bullae larger; upper incisors larger, but equally strongly recurved; molariform teeth larger.

Topotypes of ocius can be distinguished from those of _Thomomys talpoides uinta_ as follows: Color: Lighter throughout, grayish as opposed to brown. Skull: Nasals rounded posteriorly as opposed to emarginate; zygomatic arches more robust; interparietal pentagonal as opposed to subquadrangular; extension of supraoccipital posterior to lambdoidal suture markedly greater; tympanic bullae actually as well as relatively much larger; upper incisors short and strongly recurved as opposed to long and procumbent.

Specimens of this subspecies can be distinguished from all other members of the species _Thomomys talpoides_ occurring in Utah by their grayish color, and by small, compact skulls with very large tympanic bullae and short strongly recurved upper incisors.

_Remarks._--Two specimens from Vernal, Uintah County, are intergrades between _ocius_ and _uinta_. They resemble _uinta_ in size and dorsal color, but are slightly lighter tending toward the color of _ocius_. Ventrally they are intermediate in color but more like _ocius_. The skulls are more like those of _ocius_ in general appearance, extension of supraoccipital posterior to the lambdoidal suture, shape and thickness of the zygomatic arches, posterior tongues of premaxillae, size of tympanic bullae and recurved upper incisors. They more closely resemble _uinta_ in shape of posterior ends of nasals, basioccipital and shape of the zygomatic processes of the squamosals. In all of the above mentioned characters, they are intermediate between the two named forms, but tend towards one or the other as listed. The majority of characters are more as in _ocius_ to which they are here referred.

When Goldman (1939:233, 234) listed the named subspecies of _Thomomys talpoides_, he hesitated to include _ocius_ and merely mentioned that _ocius_, _pygmaeus_ and _idahoensis_ might also belong to _talpoides_. Davis (1939:240, 241) found intergradation between _idahoensis_ and _fuscus_ and also between _idahoensis_ and _pygmaeus_, and, therefore, arranged the last two mentioned forms as subspecies of _talpoides_. This present study reveals intergradation between _ocius_ and _uinta_, and also between _ocius_ and _fossor_ (see account of _fossor_). Therefore, _ocius_ is properly to be treated as a subspecies of the series of intergrading forms of which _talpoides_ is the earliest named.

All specimens of _ocius_ known from Utah are from the extreme eastern part of the northeastern corner of the state. The type locality of _ocius_ is near Fort Bridger, Wyoming, which is north of Utah. I have seen one specimen from 12 miles west of Linwood, Daggett County, Utah, on Henrys Fork in Wyoming. Additional collecting in northern Utah probably will reveal _ocius_ to inhabit also parts of northern Utah.

_Specimens examined._--Total, 4, distributed as follows:
_Uintah County_: Vernal, 2 (C. M.); Uncompahgre Indian
Reservation, 2 (A. M. N. H.).

=Thomomys talpoides moorei= Goldman

_Thomomys fossor moorei_ Goldman, Journ. Washington Acad.
Sci., 28:335, July 15, 1938.

_Thomomys talpoides moorei_ Goldman, Journ. Mamm., 20:234,
May 14, 1939.

_Type._--Male, adult, skin and skull, No. 248222, U. S. National Museum (Biological Surveys Collection); 1 mi. S Fairview, 6,000 ft., Sanpete County, Utah; February 19, 1928; collected by A. W. Moore; X-catalogue number 24799 (after Goldman, type not seen).

_Range._--Wasatch Plateau in Sanpete, Utah, Carbon and Emery counties, and in Wasatch Mountains south of Spanish Fork Canyon.

_Diagnosis._--Size medium (see measurements). Color: Upper parts between Cinnamon and Sayal Brown, with mixture of black hairs, grading through Cinnamon on sides and flanks to Pale Pinkish Buff on underparts, clearest on inguinal and pectoral regions; nose and cheeks dusky; postauricular patches medium in size and black; ears black; chin buffy white; front and hind feet white; tail mostly white with brownish hairs on dorsal surface. Skull: Large, robust; nasals long and deeply emarginate on posterior ends, and dilated distally; zygomatic arches robust and widely spreading; zygomatic processes of maxillae heavy; interparietal comparatively small, but always wider than long; extension of premaxillae posterior to nasals short; tympanic bullae moderate in size, but markedly inflated ventrally; pterygoid hamulae long; interpterygoid space narrowly V-shaped; upper incisors long and moderately recurved; molariform teeth light.

_Comparisons._--Topotypes of _moorei_ differ from topotypes and near topotypes of _Thomomys talpoides uinta_ as follows: Size slightly larger. Color: Upper parts and sides lighter; tail lighter; postauricular patches larger and darker; ears more pointed, smaller and darker. Skull: Larger, heavier and more massive; nasals longer, but deeply emarginate posteriorly as in _uinta_; rostrum wider and longer; zygomatic arches heavier and more angular; zygomatic processes of maxillae heavier; interparietal generally smaller and shorter; braincase wider; tympanic bullae more inflated ventrally; interpterygoid space more narrowly V-shaped; upper incisors longer, but not as procumbent; molariform teeth smaller.

Topotypes of _moorei_ can be distinguished from those of _Thomomys talpoides oquirrhensis_ as follows: Size slightly larger; tail longer; ears larger, less pointed. Color: Lighter throughout; postauricular patches larger. Skull: More ridged and angular; nasals narrower posteriorly, but more dilated distally; posterior ends of nasals more deeply emarginate (while shallowly emarginate in _oquirrhensis_, they tend to be somewhat rounded); rostrum narrower; extension of premaxillae posterior to nasals greater; least interorbital breadth less; zygomatic arches more angular and widely spreading; zygomatic processes of maxillae heavier; interparietal smaller; tympanic bullae larger and more inflated ventrally; upper incisors generally longer.

The characters that distinguish _moorei_ from _Thomomys talpoides parowanensis_ are: Color: Lighter throughout. Skull: Broader, more angular and more nearly flat; zygomatic arches more widely spreading; zygomatic processes of maxillae heavier; posterior ends of nasals emarginate rather than rounded; upper incisors longer.

For comparisons of _moorei_ with _Thomomys talpoides levis_ and _wasatchensis_ see accounts of these forms.

_Remarks._--Specimens from Colton, show intergradation between _moorei_, _uinta_ and _wasatchensis_, but are referable to _moorei_ in the majority of characters. Specimens from Mount Nebo, and the mouth of Reddicks Canyon, in the Wasatch and San Pitch mountains, respectively, are intergrades between _moorei_ and _wasatchensis_, but are referable to _moorei_.

That part of the Wasatch Mountains south of Spanish Fork Canyon is inhabited by pocket gophers that are intergrades between _moorei_ and _wasatchensis_, but the cranial details show them to be referable to _moorei_. The range here ascribed to _moorei_ consists of the Wasatch Plateau to the east of Sanpete Valley, the San Pitch Mountains and the southern part of the Wasatch Mountains. The type locality of _moorei_ is situated in the southern end of a high valley that separates the Wasatch Plateau from the San Pitch and Wasatch mountains. Topotypical animals are larger and have more ridged, angular skulls than those from the mountains.

_Specimens examined._--Total, 48, distributed as follows:
_Utah County_: Near Payson Lake, 1 (R. H.); Mt. Nebo, 25 mi.
SE Payson, 10,000 ft., 20; Colton, 8 (B. Y. U.). _Sanpete
County_: 1 mi. S Fairview, 6,000 ft., 12 (U. S. N. M.).
_Juab County_: Mouth of Reddicks Canyon, Wales Mountain (=
San Pitch Mountains), 7,500 ft., 5. _Emery County_: Lake
Creek, 11 mi. E Mt. Pleasant, 2 (C. M.).

_Additional records._--_Sanpete County_: Ephraim, 5 (see
Goldman, 1938:336).

=Thomomys talpoides fossor= Allen

_Thomomys fossor_ Allen, Bull. Amer. Mus. Nat. Hist., 5:51,
April 28, 1893; Bailey, N. Amer. Fauna, 39:111, November 15,
1915; Barnes, Bull. Univ. Utah, 12 (No. 15):85, April, 1922;
Bull. Univ. Utah, 17 (No. 12):102, June, 1927; Hall, Univ.
California Publ. Zooel., 37:4, April 10, 1931.

_Thomomys talpoides fossor_ Goldman, Journ. Mamm., 20:234,
May 14, 1939.

_Type._--Male, adult, skin and skull, No. 5240/4120, American Museum of Natural History; Florida, 7,200 ft., La Plata County, Colorado; June 25, 1892; collected by Charles P. Rowley (after Allen, type not seen).

_Range._--In the mountains of San Juan and Grand counties, east of the Colorado and Green rivers.

_Diagnosis._--Size medium (see measurements). Color: Upper parts Dresden Brown, grading over sides to Pale Buff on underparts; chin white; ears small, pointed, with deeply pigmented pinnae; postauricular patches grayish black; nose dusky. Skull: Long and narrow; nasals long, rounded proximally and usually simple distally; rostrum long; interparietal triangular; tympanic bullae large, and well inflated ventrally; basioccipital narrow; palate narrow; palatal pits shallow; dentition light.

_Comparisons._--Near topotypes of _fossor_ can be distinguished from topotypes of _Thomomys talpoides ocius_ as follows: Size larger throughout. Color: Darker throughout, being dark brown as opposed to grayish. Skull: Longer and narrower; nasals and rostrum longer; extension of supraoccipital posterior to lambdoidal suture markedly less; tympanic bullae markedly smaller; upper incisors longer and not as strongly recurved.

Among the races of _Thomomys talpoides_ occurring in Utah, _fossor_ most closely resembles _Thomomys talpoides uinta_ in color and size, but differs from it as follows: Ears smaller, more pointed and with more darkly pigmented pinnae. Skull: Longer, narrower and weaker; rostrum longer; nasals longer, and rounded proximally as opposed to markedly emarginate; interparietal triangular instead of roughly pentagonal; tympanic bullae larger and more inflated ventrally; basioccipital narrower; palate narrower, palatal pits shallower; dentition lighter.

_Remarks._--Bailey (1915:111) remarked that _fossor_ was one form that held its distinctive characters over a wide range. At that time, its range was understood to include practically all of the mountainous parts of Colorado, Utah as far west as the central part of the state, and parts of New Mexico, Arizona and Wyoming. Subsequently three new forms have been named from central Utah, (Goldman 1938:334-337) thereby showing variation to be much more prevalent than formerly supposed. The range of _fossor_ in Utah, as now understood, is limited to the mountainous parts of the state south and east of the Colorado and Green rivers in Grand and San Juan counties.

The Utah specimens are not typical. At first glance some differences are noted in the premaxillae and nasals. Four specimens in the collections of the Museum of Natural History, University of Kansas, three from 3 miles east of Creede, Mineral County, and one from 10 miles east of Lake City, Hinsdale County, Colorado, both of which lie north and east of the type locality of _fossor_ show the same characters as the Utah specimens.

Eight specimens from Oak Spring are intergrades between _fossor_ and _ocius_. In size and color they are like _fossor_, but the skulls are intermediate. Because the animals are more like _fossor_ in the majority of characters, they are here referred to that race.

As a result of these studies and due to the paucity of specimens from Utah, it is advisable, for the present, to refer all these Utah animals to _fossor_. Additional specimens may reveal characters that will merit the separation of the Utah animals from typical _fossor_; a desertlike area unfavorable to _Thomomys_ exists between the type locality and eastern Utah.

_Specimens examined._--Total, 21, distributed as follows:
_Grand County_: Oak Spring, Middle Fork Willow Creek, 15 mi.
N Thompson, 8 (C. M.); La Sal Mountains, 1 (U. S. N. M.);
Warner Ranger Station, La Sal Mountains, 3 (B. Y. U.). _San
Juan County_: Geyser Pass, 18 mi. SE Moab, La Sal Mountains,
3 (1, B. Y. U.; 2, C. M.); 5 mi. W Monticello, 1 (C. M.);
Cooley Pass, 8 mi. W Monticello, 2 (C. M.); Joshua Flat, Elk
Ridge, 8,300 ft., 3 (M. V. Z.).

=Thomomys talpoides parowanensis= Goldman

_Thomomys fossor parowanensis_ Goldman, Journ. Washington
Acad. Sci., 28:334, July 15, 1938.

_Thomomys talpoides parowanensis_ Goldman, Journ. Mamm.,
20:234, May 14, 1939; Long, Journ. Mamm., 21:176, May 14,
1940.

_Thomomys fossor_ Bailey, N. Amer. Fauna, 39:112, November
15, 1915; Barnes, Bull. Univ. Utah, 12 (No. 15):85, April,
1922; Bull. Univ. Utah, 17 (No. 12):102, June, 1927; Hall,
Univ. California Publ. Zooel., 37:4, April 10, 1931;
Presnall, Zion-Bryce Mus. Bull., 2:14, January, 1938;
Tanner, Great Basin Nat., 1:111, 1940.

_Type._--Male, adult, skin and skull, No. 158072, U. S. National Museum (Biological Surveys Collection); Brian Head, Parowan Mountains, 11,000 ft., Iron County, Utah; September 8, 1908; collected by W. H. Osgood; original number 3483 (after Goldman, type not seen).

_Range._--High mountains of eastern Iron and Beaver counties, and western Kane and Garfield counties.

_Diagnosis._--Size medium (see measurements). Color: Upper parts Sayal Brown moderately mixed with black, lightest on head; sides lightly washed with Buff; underparts Pinkish Buff, clearest on inguinal and pectoral regions; nose and cheeks dusky; postauricular patches large and black; front feet, hind feet and distal half of tail white. Skull: Long and fairly slender; zygomatic arches not widely spreading; nasals long; rostrum long and slender; posterior ends of nasals truncate or moderately emarginate; extension of premaxillae posterior to nasals usually short; tympanic bullae relatively small; upper incisors long and narrow; molariform teeth large.

_Comparisons._--Compared with _Thomomys talpoides kaibabensis_, _parowanensis_ differs as follows: Size smaller. Skull: Shorter; nasals shorter; zygomatic breadth less; nasals truncate or shallowly emarginate posteriorly as opposed to rounded; upper incisors narrower.

Topotypes of _parowanensis_ differ from topotypes and near topotypes of _Thomomys talpoides uinta_ as follows: Size larger. Color: Usually lighter; postauricular patches larger and darker; ears small with pinnae deeply pigmented as opposed to large and lightly pigmented. Skull: Larger; zygomatic arches more widely spreading; nasals longer; rostrum longer; posterior ends of nasals truncate or shallowly emarginate as opposed to deeply emarginate; sides of zygomatic arches nearly parallel and not so divergent posteriorly; interparietal larger and less quadrangular; extension of premaxillae posterior to nasals less; upper incisors less procumbent; molariform teeth larger.

Among named races of _Thomomys talpoides_, _parowanensis_ most closely resembles _levis_, the race nearest geographically to the east, but differs from _levis_ as follows: Size larger. Skull: Longer and wider; rostrum and nasals longer; interparietal quadrangular as opposed to roughly elliptical; upper incisors longer.

For comparisons with _Thomomys talpoides moorei_ and _wasatchensis_ see accounts of those forms.