skulls are the largest of any species or subspecies of _Thomomys_ found
in Utah. In total length, however, these animals are no longer than the
extremes found in other named races. When Goldman (1942:75) described
this race as new, he referred it to the species _Thomomys townsendii_,
but remarked that the animal from Richfield was different enough from
any other form then named to merit probably full specific status. I
know of no character other than size to separate _Thomomys townsendii_
from _Thomomys bottae_, and since intergradation has been shown to
exist between these alleged _townsendii_ from Richfield and animals
from extreme western Utah known to belong to the species _bottae_,
_lenis_ is here arranged as a subspecies of _Thomomys bottae_ which
name has priority over _Geomys townsendii_.
The range here ascribed to this race is the Sevier River Valley from
Piute County as far downstream as the town of Lynndyl which is near the
eastern mainland of Pleistocene Lake Bonneville. The Sevier River
continues farther out into Delta Valley ultimately to empty into Sevier
Lake, which at present is adjacent to the area that formerly
constituted the western mainland of the aforementioned ancient lake.
This watercourse may have provided a migration route in ancient times,
during the fluctuations of Lake Bonneville, whereby the animals
formerly of the western mainland were able to come far eastward. The
animals from Lynndyl which are intergrades between _lenis_, an eastern
mainland form, and _centralis_ and _aureiventris_ which are western
mainland forms of Lake Bonneville lend support to this hypothesis.
_Specimens examined._--Total, 26, distributed as follows:
_Millard County_: Lynndyl, 4,796 ft., 21. _Juab County_: U.
B. (= Yuba) Dam, 5,000 ft., 1. _Sevier County_: Salina,
4,575 ft., 1; Richfield, 5,308 ft., 3. (U. S. N. M.).
=Thomomys bottae levidensis= Goldman
_Thomomys bottae levidensis_ Goldman, Proc. Biol. Soc.
Washington, 55:76, June 25, 1942.
_Thomomys perpallidus aureus_ Bailey, N. Amer. Fauna, 39:75,
November 15, 1915; Barnes, Bull. Univ. Utah, 12 (No. 15):85,
April, 1922; Bull. Univ. Utah, 17 (No. 12):100, June, 1927.
_Type._--Male, adult, skin and skull, No. 191962, U. S. National Museum
(Merriam Collection); Manti, 5,500 ft., Sanpete County, Utah; December
6, 1888; collected by Vernon Bailey; original number 427 (after
Goldman, type not seen).
_Range._--San Pitch River Valley, Sanpete County, Utah.
_Diagnosis._--Size small (see measurements). Color: Upper parts and
sides Cinnamon Buff, finely mixed with black along median line of back;
underparts Pinkish Buff; nose, cheeks and chin grayish black;
postauricular patches fairly large and grayish black; front and hind
feet white (examples from type series badly stained); tail light buff
but apparently white distally (the color of these specimens has
apparently changed with age). Skull: Small, fairly robust; basilar
length short; zygomatic arches weak, but widely spreading; tympanic
bullae small; nasals short and simple distally; ventral margin of
jugals convex dorsally; extension of premaxillae posterior to nasals
relatively as well as actually long; posterior tongues of premaxillae
relatively wide.
_Comparisons._--Topotypes of _levidensis_ differ from those of
_Thomomys bottae absonus_ as follows: Size smaller. Color: Lighter
throughout. Skull: Shorter, weaker and less ridged and angular, but
relatively wider.
Compared with topotypes of _Thomomys bottae albicaudatus_, _levidensis_
differs as follows: Size smaller in every measurement taken. Color:
Markedly lighter throughout. Skull: Smaller in every measurement taken;
width relatively greater; skull smooth, weak and nonangular as opposed
to ridged, robust and angular.
For comparisons with _Thomomys bottae lenis_ and _contractus_ see
accounts of those forms.
_Remarks._--The range here ascribed to _levidensis_ is the San Pitch
River Valley, which gradually merges southward into the Sevier River
Valley. The latter valley in this area is inhabited by pocket gophers
that belong to another subspecies, _lenis_. Nephi Valley to the west of
San Pitch River Valley is inhabited by animals belonging to the
subspecies _albicaudatus_. No known specimens show intergradation
between _lenis_ and _levidensis_, but intergradation between _lenis_
and _albicaudatus_ is noted in the Nephi Valley animals (see account of
_albicaudatus_). Superficially _levidensis_ resembles _absonus_ in size
and color, but the skulls closely resemble those of _albicaudatus_,
except for size in which they are smaller in all measurements. _T. b.
albicaudatus_ is the most variable subspecies of _T. bottae_ occurring
in Utah, and additional material from the Sevier River Valley between
San Pitch River Valley and Nephi Valley may show _levidensis_ to be
only a local variant of the highly variable subspecies, _albicaudatus_.
_Specimens examined._--Total, 6, from the type locality.
=Thomomys bottae osgoodi= Goldman
_Thomomys perpallidus osgoodi_ Goldman, Journ. Washington
Acad. Sci., 21:424, October 19, 1931.
_Thomomys bottae osgoodi_ Goldman, Proc. Biol. Soc.
Washington, 48:156; October 31, 1935.
_Thomomys perpallidus aureus_ Bailey, N. Amer. Fauna, 39:75,
November 15, 1915; Barnes, Bull. Univ. Utah, 12 (No. 15):85,
April, 1922; Bull. Univ. Utah, 17 (No. 12):100, June, 1927.
_Type._--Male, adult, skin and skull, No. 158530, U. S. National Museum
(Biological Surveys Collection); Hanksville, Wayne County, Utah;
October 20, 1908; collected by W. H. Osgood; original number 3701
(after Goldman, type not seen).
_Range._--Eastern Utah in the valleys of the drainage of the San
Rafael, Dirty Devil and Price rivers.
_Diagnosis._--Size medium (see measurements). Color: Upper parts near
(_e_) Pale Ochraceous Buff, definitely yellow in appearance; sides Pale
Ochraceous Buff; entire underparts white, with a wash of Light Buff in
the pectoral and inguinal regions; top of head, nose, cheeks, and chin
dusky; postauricular patches grayish black; front feet, hind feet and
distal part of tail white. Skull: Fairly robust but narrow; zygomatic
arches concave medially in mid-jugal region; skull moderately convex
dorsally, due to swelling in region of base of rostrum; lambdoidal
suture situated well ahead of posterior margin of skull, with
supraoccipital forming a side shelf at posterior part of skull;
interpterygoid space narrowly V-shaped; tympanic bullae well inflated
ventrally; basioccipital short; nasals rounded posteriorly; molariform
teeth large.
_Comparisons._--Topotypes of _osgoodi_ differ from those of _Thomomys
bottae absonus_ as follows: Size generally smaller. Color: Lighter
throughout, more yellowish in appearance as opposed to buffy. Skull:
Smaller in all measurements, except length of nasals, mastoid breadth,
and alveolar length of upper molar series which are larger; rostrum
shorter but relatively wider; zygomatic arches more robust and concave
medially; palate wider; supraoccipital more bulging posteriorly;
tympanic bullae more inflated ventrally; molariform teeth larger.
For comparisons with _Thomomys bottae aureus_ and _T. b. dissimilis_
see accounts of those forms.
_Remarks._--The animals here referred to _osgoodi_ are remarkably
uniform in color, but vary widely in cranial details. Specimens from
Carbon County are not typical and when more material becomes available
it may prove that these animals from the northern part of the range of
_osgoodi_ will merit separation and naming. The specimens from Emery
County are not typical but resemble _osgoodi_ more than do the animals
from Carbon County.
The range here ascribed to _osgoodi_ is in that part of the eastern
Utah desert that is bounded on the east by the Green and Colorado
rivers, on the west by the high mountains of central Utah, on the north
by the Book Cliffs and on the south by the Dirty Devil River. This area
is an uninviting wasteland in which there are relatively few roads and
little water. In addition, it is greatly cut up by washes and gullies
which contain water only during a few weeks of the year. The
continuation of this area of wasteland southward beyond the Dirty Devil
River is inhabited by pocket gophers belonging to the subspecies
_absonus_. If specimens were available they would undoubtedly show
intergradation to exist between _osgoodi_ and _absonus_.
_Specimens examined._--Total, 14, distributed as follows:
_Carbon County_: 1-2 mi. N Spring Glen, 6,150 ft., 2; Spring
Glen, 6,200 ft., 2; 2 mi. E Spring Glen, 6,200 ft., 1.
_Emery County_: Price River, 2 mi. SE Woodside, 4,600 ft., 2
(C. M.); Green River, 4,080 ft., 5 (M. V. Z.). _Wayne
County_: Hanksville, 2 (U. S. N. M.).
=Thomomys bottae howelli= Goldman
_Thomomys bottae howelli_ Goldman, Journ. Washington Acad.
Sci., 26:116, March 15, 1936.
_Type._--Female, adult, skin and skull, No. 25684, U. S. National
Museum (Biological Surveys Collection); Grand Junction, 4,600 ft., Mesa
County, Colorado; November 7, 1895; collected by A. H. Howell; original
number 493 (after Goldman, type not seen).
_Range._--In the valleys of eastern Utah, east of the Green River and
north of the Colorado River.
_Diagnosis and Comparisons._--Inasmuch as there is but one specimen,
the holotype known, and as it was impossible to study it, the following
diagnoses and comparisons are from Goldman, (1936:116).
"_General characters._--A rather large, pallid subspecies with a broad,
flattened cranium. Similar to the palest specimens of _Thomomys bottae
aureus_ of the San Juan River Valley, southeastern Utah, in color, but
underparts more thinly overlaid with buffy white, and cranial
characters, especially the broad, flat braincase, distinctive.
Approaching _Thomomys bottae osgoodi_ of the Fremont River Valley,
Utah, in color, but much larger and skull widely different.
"_Color._--Type (winter pelage): Upper parts in general between tilleul
buff and pale olive buff (Ridgway 1912), somewhat darkened on head by a
mixture of cinnamon buff and brown; a few inconspicuous dusky-tipped
hairs along median line of back; muzzle dusky; ears and postauricular
spots deep, contrasting black; underparts thinly overlaid with buffy
white, the hairs becoming pure white to roots on inguinal region;
thighs pure white to roots all around; feet white; tail buffy whitish,
slightly paler below than above.
"_Skull._--Similar in general to that of _T. b. aureus_, but braincase
conspicuously broader and flatter; zygomata more widely spreading;
nasals shorter; premaxillae more attenuate posteriorly; interparietal
larger; audital bullae more rounded and fully inflated anteriorly;
incisors short, as in _aureus_, but less strongly recurved. Compared
with that of _T. b. osgoodi_ the skull is much larger, with flatter
braincase, shorter nasals, and posteriorly narrower premaxillae."
_Remarks._--Six specimens, in the Carnegie Museum from 10 miles north
of Moab, Grand County, Utah, were available for this study. They are
not typical of _howelli_ as it is diagnosed by Goldman (_loc. cit._).
They appear to be intergrades between _howelli_ and _osgoodi_ in
cranial characters, but more closely resemble _howelli_, particularly
in the flat, widened, low braincase. In color, some specimens seem to
intergrade toward _aureus_.
The range ascribed to this form in Utah appears to be one of the most
natural ones within the state since it is bounded by the Green and
Colorado rivers which have formed deep rocky gorges in this region.
_Specimens examined._--Total, 6, as follows: _Grand County_:
10 mi. N Moab, 6 (C. M.).
=Thomomys bottae wahwahensis= Durrant
_Thomomys bottae wahwahensis_ Durrant, Bull. Univ. Utah, 28
(No. 4):4, August 18, 1937.
_Type._--Male, adult, skin and skull, No. 1750, Museum of Zooelogy,
University of Utah, Wah Wah Springs, 30 mi. W Milford, 6,500 ft.,
Beaver County, Utah; July 22, 1936; collected by S. D. Durrant;
original number 989.
_Range._--Westcentral Utah, in Wah Wah Mountains, and Pine Valley to
the west of these mountains.
_Diagnosis._--Size medium (see measurements). Color: Upper parts
Pinkish Buff; underparts Pale Pinkish Buff with considerable admixture
of gray; inguinal and pectoral regions Pale Pinkish Buff; nose and
cheeks grayish black; postauricular patches small and black; front
feet, hind feet and distal one-third to one-half of tail white. Skull:
Flat dorsoventrally; rostrum short and wide; premaxillae broad and
heavy; nasals short and straight, with no arching as viewed laterally;
tympanic bullae small; space enclosed within zygomatic arches short
antero-posteriorly; alveolar length of upper molar series short;
molariform teeth small.
_Comparisons._--From topotypes of _Thomomys bottae centralis_,
_wahwahensis_ differs as follows: Size smaller in every measurement
taken. Color: Lighter, Pinkish Buff as opposed to Cinnamon Buff. Skull:
Rostrum wider, shorter and more nearly flat; nasals straight as opposed
to moderately convex; tympanic bullae smaller and less inflated
ventrally; zygomatic arches more widely spreading and angular;
molariform teeth smaller; extension of premaxillae posterior to nasals
less.
From topotypes of _Thomomys bottae albicaudatus_, _wahwahensis_ differs
as follows: Hind foot shorter. Color: Lighter throughout, Pinkish Buff
as opposed to (13''''_n_) Black. Skull: Smaller and more nearly flat;
rostrum shorter, wider and more nearly flat; nasals straight as opposed
to convex; zygomatic breadth less but mastoid breadth greater; tympanic
bullae smaller, and less inflated ventrally; extension of premaxillae
posterior to nasals less; molariform teeth smaller.
From topotypes of _Thomomys bottae aureiventris_, _wahwahensis_ differs
in the following features: Size smaller; hind foot shorter. Color:
Lighter throughout, no "gold" on underparts. Skull: Smaller in nearly
every measurement taken; rostrum shorter and relatively wider;
zygomatic arches more angular and relatively more widely spreading;
nasals shorter and more nearly flat; thickening at union of jugal and
zygomatic process of maxilla less; interpterygoid space V-shaped as
opposed to lyre-shaped; tympanic bullae much smaller, and less inflated
ventrally; molariform teeth much smaller.
Topotypes of _wahwahensis_ can be easily distinguished from those of
_Thomomys bottae tivius_ by their markedly larger size in every
measurement taken, lighter color, and larger, more robust and more
nearly flat skull.
For comparisons of _wahwahensis_ with _Thomomys bottae sevieri_,
_robustus_, _bonnevillei_ and _convexus_ see comparisons under those
forms.
Among the named races of _Thomomys bottae_, _wahwahensis_ definitely
has its affinities with _planirostris_ from Zion National Park. Both
possess flat skulls with wide, short rostra. It differs from the latter
in: Size smaller in every measurement taken. Color: Lighter throughout.
Skulls: Nasals and rostrum shorter and more nearly flat; tympanic
bullae markedly smaller; alveolar length of upper molar series shorter;
molariform teeth markedly smaller and weaker.
_Remarks._--Wah Wah Springs, the type locality of _wahwahensis_, are on
the summit of a low pass in the Wah Wah Mountains in the desert of west
central Utah. The surrounding valleys, for many miles, as far as my
investigations show, are not inhabited by pocket gophers, except the
Desert Range Experiment Station of the United States Forest Service in
Pine Valley to the west of these mountains. There, pocket gophers were
obtained which are intergrades between _centralis_ and _wahwahensis_.
In five out of seven characters investigated these gophers resemble
_wahwahensis_, to which they are here referred. Study of the topography
reveals the probable means by which the animals reached this valley.
The long axis of the Wah Wah Mountains is north and south, but a
westward arm forms the northern boundary of Pine Valley. Around springs
in this westward projecting arm workings of pocket gophers were found.
With the development of water at the Desert Range Experiment Station,
and subsequent improvement of forage, these animals probably came down
into the valley from the springs to the north.
The terrain between the Desert Range Experiment Station in Pine Valley
and Snake Creek (where _centralis_ occurs) to the west is not inhabited
by pocket gophers at present. This area, however, forms part of the
southwest mainland of Pleistocene Lake Bonneville, which mainland in
times past was probably suitable for pocket gophers. Since the close of
the Pleistocene, aridity has rendered most of it unfit for pocket
gophers, and they remain only in isolated areas where suitable
environments still persist.
_Specimens examined._--Total, 18, distributed as follows:
_Millard County_: Desert Range Experiment Station, United
States Forest Service, Sec. 9, T. 25 S, R. 17 W, Salt Lake
Base Meridian, 6. _Beaver County_: Wah Wah Springs, Wah Wah
Mountains, 30 mi. W Milford, 6,500 ft., 12 (2, M. V. Z.).
=Thomomys bottae dissimilis= Goldman
_Thomomys perpallidus dissimilis_ Goldman, Journ. Washington
Acad. Sci., 21:425, October 19, 1931.
_Thomomys bottae dissimilis_ Goldman, Proc. Biol. Soc.
Washington, 48:156, October 31, 1935.
_Thomomys perpallidus aureus_ Bailey, N. Amer. Fauna 39:75,
November 15, 1915; Barnes, Bull. Univ. Utah, 12 (No. 15):85,
April, 1922; Bull. Univ. Utah, 17 (No. 12):100, June, 1927.
_Type._--Female, adult, skin and skull, No. 158526, U. S. National
Museum (Biological Surveys Collection); E slope Mount Ellen, Henry
Mountains, 8,000 ft., Garfield County, Utah; October 15, 1908;
collected by W. H. Osgood; original number 3677 (after Goldman, type
not seen).
_Range._--Known only from the type locality.
_Diagnosis._--Size small (see measurements). Color: Upper parts Light
Buff, grading over sides to nearly white on underparts; underparts
lightly washed with Pale Buff, more marked in inguinal and pectoral
regions; postauricular patches grayish black; nose, chin, cheeks and
top of head dusky; front feet, hind feet and distal half of tail white.
Skull: Small and weak; zygomatic arches long, but lying close to skull,
giving it a slender appearance; supraoccipital markedly projecting
posteriorly from lambdoidal suture; rostrum relatively long and narrow;
nasals long; tympanic bullae well inflated ventrally, with a median
ventral ridge; pterygoid hamulae weak; interpterygoid space narrowly
V-shaped; upper incisors short and light in color; molariform teeth
relatively large.
_Comparisons._--Comparison of one topotype of _dissimilis_ with
topotypes of _Thomomys bottae aureus_ shows it to differ as follows:
Size smaller throughout. Color: Lighter dorsally and on sides, pale
buff as contrasted with rich ochraceous; underparts more buffy. Skull:
Smaller in every measurement taken; zygomatic arches markedly less
widely spreading; braincase narrower and more vaulted; tympanic bullae
with a median ventral ridge as opposed to smooth; pterygoid hamulae
slenderer; interpterygoid space narrowly V-shaped as opposed to
U-shaped; upper incisors smaller and lighter in color.
Compared with topotypes of _Thomomys bottae absonus_, _dissimilis_
differs in the following features: Size smaller in every measurement
taken. Color: Lighter throughout. Skull: Smaller in every measurement
taken, except alveolar length of upper molar series which is greater;
skull narrower and weaker; zygomatic arches weaker and less widely
spreading; tympanic bullae more ridged on ventral surface and shorter
(more rounded) in antero-posterior measurement; upper incisors shorter
and narrower; molariform teeth larger.
_Thomomys bottae dissimilis_ resembles _T. b. osgoodi_ more than any
other subspecies but differs in: Size smaller throughout. Color:
Slightly darker dorsally. Skull: Smaller in every measurement taken,
and slenderer; rostrum relatively longer; zygomatic arches weaker, and
less widely spreading, more converging anteriorly; tympanic bullae less
rounded, more ridged medioventrally; upper incisors shorter but
narrower; molariform teeth smaller.
_Remarks._--The Henry Mountains, in eastern Garfield County, are in the
Colorado River drainage. The surrounding country is desertlike and cut
by gullies and washes with sheer escarpments and precipitous draws. The
type locality of _dissimilis_ is possibly in an isolated area. Only
three specimens were available to Goldman when he named _dissimilis_.
He commented on the close resemblance to _osgoodi_ which inhabits the
country to the north. I have examined only one of the three specimens
available to Goldman. Although I can see the characters that he
mentioned, I am not fully convinced that _dissimilis_ is separable from
_osgoodi_. Two specimens from Escalante, Garfield County, are referred
to _absonus_, but they show intergradation with _dissimilis_.
_Specimens examined._--One (U. S. N. M.) from E slope Mount
Ellen, Henry Mountains, 8,000 ft., Garfield County.
=Thomomys bottae aureus= Allen
_Thomomys aureus_ Allen, Bull. Amer. Mus. Nat. Hist., 5:49,
April 28, 1893.
_Thomomys bottae aureus_ Goldman, Proc. Biol. Soc.
Washington, 48:156, October 31, 1935; Benson, Univ.
California Publ. Zooel., 40:450, December 31, 1935.
_Thomomys fulvus aureus_ Goldman, Journ. Washington Acad.
Sci., 21:417, October 19, 1931; Journ. Washington Acad.
Sci., 23:464, October 15, 1933.
_Thomomys perpallidus aureus_ Bailey, N. Amer. Fauna, 39:74,
November 15, 1915; Barnes, Bull. Univ. Utah, 12 (No. 15):85,
April, 1922; Bull. Univ. Utah, 17 (No. 12):100, June, 1927.
_Type._--No. 5243/4123. American Museum of Natural History; Bluff City,
San Juan County, Utah; May 12, 1892; collected by Charles P. Rowley
(after Allen, type not seen).
_Range._--All of San Juan County (except extreme southwestern part) and
Grand County east of the Colorado River.
_Diagnosis._--Size large (see measurements). Color: Upper parts
Cinnamon Buff, lighter on sides; underparts generally white, or if
colored at all with only a faint wash of Light Buff; nose and chin
blackish gray; top of head blackish due to admixture of black hairs;
postauricular patches small and dusky; front feet and hind feet white.
Skull: Long, narrow but massive; zygomatic arches not widely spreading,
but heavy; jugals thick, union of jugals and zygomatic processes of
maxillae thickened; rostrum long but wide; top of rostrum convex in
lateral view; ascending processes of premaxillae wide and heavy; nasals
thin proximally; braincase long and narrow; tympanic bullae well
inflated ventrally; alveolar length of upper molar series long; molars
large; pterygoid hamulae heavy; interpterygoid space U-shaped; palate
arched; upper incisors long and wide.
_Comparisons._--Compared with topotypes of _Thomomys bottae osgoodi_,
_aureus_ differs as follows: Size larger in every measurement taken,
except tail which is shorter. Color: Darker throughout except on
ventral surface which is lighter. Skull: Larger, longer and wider;
nasals longer; rostrum wider and longer; zygomatic arches more nearly
straight and heavier; ascending processes of premaxillae wider;
basioccipital longer; interpterygoid space U-shaped as opposed to
V-shaped; tympanic bullae larger; upper incisors longer, wider; molars
larger.
Topotypical specimens of _aureus_ can be distinguished from those of
_Thomomys bottae dissimilis_ by: Size larger throughout. Color: A
trifle darker on dorsal surface. Skull: Larger in every measurement
taken; zygomatic arches heavier and more nearly straight; tympanic
bullae larger and more inflated ventrally; interpterygoid space
U-shaped as opposed to V-shaped; alveolar length of upper molar series
longer; molars larger; upper incisors longer and wider.