North American fauna

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UNITED STATES DEPARTMENT OF THE INTERIOR

FISH AND WILDLIFE SERVICE

THE POCKET GOPHERS
(GENUS THOMOMYS) OF ARIZONA

NORTH AMERICAN FAUNA 59

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| MAR d 1 2000 (

UNITED STATES DEPARTMENT OF THE INTERIOR
J. A. Krug, Secretary

FISH AND WILDLIFE SERVICE
Albert M. Day, Director

North American Fauna 59

THE POCKET GOPHERS
(GENUS THOMOMYS) OF ARIZONA

BY

EDWARD A. GOLDMAN

UNITED STATES

GOVERNMENT PRINTING OFFICE

WASHINGTON : 1917

For Sue by the Superintendent of Documents. U. S. Government I'rintinu' Office

Washington i'.">. I). ('. Price i"> cents

4 NORTH AMERICAN FAUNA 59, FISH AND WILDLIFE SERVICE

a mountain meadow. In such places the burrows may be close to-
gether, with many mounds of excavated earth dotting the surface
and tunnels interspersed. Numerous mounds may mark the oper-
ations of one or several individuals, but studies indicate that each
burrow occupant, male or female, is solitary, except during the
mating season and during the time that the young must remain
in the same tunnels with their mother. Colonies may be more or
less isolated by areas of nearly impervious soil or by rock forma-
tions, with breeding connections between them uncertain. Below the
upper walls of the Grand Canyon one form, muralis, was found
living in isolated strips of soil only a few feet wide, bounded above
and below by vertical cliffs about 300 feet high. It presents rath-
er well marked characters, and in this and a few similar cases
the use of full specific names seems warranted, although the close
relationship to a neighboring form is also clearly evident.

Response to environmental conditions is shown by the marked
tendency of pocket gophers to assume the colors of the soils in
which they burrow. This tendency is shared with many other
mammals, but is especially noteworthy in the forms of the Tho-
momys bottae group. Pocket gophers of this group inhabiting
light-colored sand are usually light shades of buff, varying to al-
most white ; those living in reddish soils assume ruf escent tones ;
and those from blackish terrain, especially dark volcanic soils,
are usually deeper reddish or dark brown, and may vary to black
in some specimens. Occasional melanistic individuals may occur
anywhere, but black or blackish specimens are more prevalent in
lava areas. Pocket gophers inhabiting soft, sandy ground or al-
luvial bottomlands, where food is more abundant, or more acces-
sible, tend to be larger than those inhabiting more rocky or ster-
ile areas.

THOMOMYS BAILEYI GROUP

The Thomomys buileyi group (fig. 2), as recognized, embraces
several races ranging in western Texas, parts of southern New
Mexico (except the Rio Grande Valley), northern Chihuahua, and
west to southeastern Arizona, where the group is represented by
T. b. mearnsi. In some of the more important characters these
races agree with those of the bottae group, but the zygomata are
slender with slight expansion of the maxillary arm near the line
of contact with the jugal, the rostrum is of shallow depth, and
the upper incisors are strongly procumbent. Representatives of
the two groups taken in the same vicinity appear to be distinct.

THE POCKET GOPHERS

Figure 2. — Distribution of subspecies of Thomomys talpoides, T. umbrinus, and
T. bailey i groups in Arizona:

1. T. t. kaibabensis.

2. T. t. fossor.

3. T. u. proximus.

4. T. u. burti.

5. T. u. quercinus.

6. T. u. intermedius.

7. T. b. meainsi.

THOMOMYS TALPOIDES GROUP

The Thomomys talpoides group (fig. 2) is now known to con-
stitute an assemblage of numerous forms which ranges as a whole
from Saskatchewan, Alberta, and southern British Columbia
southward in the Rocky Mountain region, and meets the distribu-
tion area of the bottae group in Nevada, southern Utah, northern
Arizona, and northwestern New Mexico. In Arizona the group
favors the higher mountains and is represented by T. t. kaibabcn-

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sis of the Kaibab Plateau and by T. t. fossor which occurs in the
Tunitcha and Lukachukai Mountains in the extreme northeastern
corner of the State.

The members of the Thomomys talpoides group are similar in
size to those of the bottae group, but the upper parts in general
are dull cinnamon buff, the back usually overlaid with rusty, the
black post-auricular spots are larger and the general coloration is
duller in tone. The mammae vary from four to six pairs (2 abdomi-
nal pairs normally present in typical talpoides). The skull is elon-
gated and slender ; rostrum long and narrow, the sides more deeply
excavated than in other groups, leaving the roots of upper incisors
clearly outlined; nasals rather broad anteriorly, gradually nar-
rowing posteriorly; zygomata slender, depressed posteriorly, the
jugals sloping upward to points of contact with maxillae ; ossified
external auditory meatus large and prominent; interparietal ex-
tends posteriorly beyond plane of posterior border of parietals;
upper incisors narrow and thin, decurved about as in bottae group.

THOMOMYS UMBRINUS GROUP

The Thomomys umbrinus group (fig. 2), composed of small
pocket gophers, is widely dispersed in Mexico. Like the bottae
group, it is subdivided into numerous geographic races, several
of which are restricted to the mountains of southeastern Arizona.

In color of upper parts the members of the umbrinus group are
between cinnamon brown and russet, varying to sayal brown in
proximus, the back usually deep black along the median line;
black post-auricular spots usually large and confluent with black
of back in some specimens. The skull is slender, with brain case
smoothly rounded, the temporal ridges inconspicuous or absent;
rostrum short, and moderately broad; nasals distinctly wedge-
shaped, narrowing posteriorly, the ends usually emarginate ; zygo-
mata slender, the sides nearly parallel; ossified auditory meatus
small ; upper incisors relatively broad and heavy, decurved in ver-
tical plane at anterior ends of nasals in Arizona forms, strongly
procumbent in numerous Mexican races.

ECONOMIC STATUS

The pocket gophers of all groups consume plant food, but their
widespread burrowing activities, which tend to stir the soil, are,
under natural conditions, beneficial to plant growth and thus in-
directly to other animals dependent on plants. Erosion of the
land surface may, however, be started by water entering the
tunnels, especially where these extend up and down steep slopes.
Beneficial habits are, therefore, offset by some destructive ef-

THE POCKET GOPHERS 7

fects, and pocket gophers seem rather negligible in the biotic
complex. The desert forms are limited in numbers by the food
supply and by natural enemies. Where desert land is brought
under irrigation and cultivation, however, the food supply is
greatly increased, predation is lessened, and the pocket gopher
population may be expected to rise inordinately unless effective
control measures are adopted. On cultivated lands severe dam-
ages result from crops directly consumed, or roots severed, and
from the tunnels which often cause breaks in irrigation ditches.

SPECIES AND SUBSPECIES OF THOMOMYS
BOTTAE GROUP

THOMOMYS BOTTAE VIRGINBUS Goldman

Virgin Valley Pocket Gophek

Thomomys bottae virgineus Goldman, Biol. Soc. Wash. Proc. 50: 133, Sep-
tember 10, 1937.

Type. — From Beaverdam Creek, near confluence with Virgin
River, at Littlefield, northwestern Arizona (altitude 1,500 feet) ;
collected by Luther C. Goldman, October 16, 1936.

General characters. — A cinnamon-buff form, similar to cen-
tralis of eastern Nevada, but skull relatively narrower, more
elongated, the zygomata less widely spreading, more distinctly
bowed inward near middle of jugals. Similar to nicholi of the
Shivwits Plateau region, but somewhat darker, and skull differ-
ing in about the same characters as from centralis.

Measurements. — Average of three adult male topotypes: Total
length, 232 (232-232) ; tail, 74 (72-75) ; hind foot, 31.5 (31-31.5)
millimeters. Two adult female topotypes, respectively, 207, 210;
62, 58 ; 28, 29.5 millimeters.

Distribution and habitat. — The range of virgineus includes the
Virgin River Valley below the canyon traversed by the river in
breaking across the fault line marked by the Beaverdam Moun-
tains on one side, and the Grand Wash Cliffs on the other, just
above the type locality. East of the Virgin Valley this form is
found in an extremely arid section near Pakoon Spring, along
Grand Wash. The general area inhabited is well down in the
Lower Sonoran Zone. On the bottomlands along Beaverdam
Creek and the Virgin River, pocket gophers are numerous
enough in some places to be destructive to alfalfa, which is grown
on a limited scale.

THOMOMYS BOTTAE NICHOLI Goldman

Shivwits Plateau Pocket Gophek

Tlwmomys bottae nicholi Goldman, Jour. Wash. Acad. Sci. 28 (7): 337, July
15, 1938.

6%493°— 47— 2

8 NORTH AMERICAN FAUNA 59, FISH AND WILDLIFE SERVICE

Type. — From 20 miles south of Wolf Hole (road to Parashonts),
Shivwits Plateau, Mohave County, Ariz, (altitude 5,000 feet) ;
collected by Luther C. Goldman, August 6, 1937.

General characters. — A light, cinnamon-buff subspecies of me-
dium size. Closely allied to trumbullensis of the neighboring Mount
Trumbull lava area, but paler buff, the back less mixed with
black. Similar to virgineus of the Virgin River Valley below the
break through the Beaverdam Mountains, but somewhat darker;
skull differing in detail, the frontals broader, zygomata more
widely spreading, and the jugals not distinctly bowed inward as
in virgineus.

Measurements. — Two adult male topotypes, respectively : Total
length, 229, 208 ; tail, 65, 59 ; hind foot, 27.5, 28 millimeters. Two
adult females from Saint George, Utah, respectively: 208, 204;
71, 63 ; 27, 27.5 millimeters.

Distribution and habitat. — The range of this pocket gopher is
the Shivwits Plateau region, on the terrace between the Hurri-
cane Ledge on the east, and the Grand Wash Cliffs on the west,
north of the Grand Canyon, northwestern Arizona. The general
area, at 4,500 to 5,000 feet, is in the lower part of the Upper So-
noran Zone, but slopes down at the north end to 2,500 feet al-
titude in the Lower Sonoran Zone at Saint George, in the Virgin
River Valley, just across the Utah boundary. The pocket gophers
occur irregularly in small, widely scattered colonies, on land com-
monly overgrown with Atriplex and sagebrush {Artemisiu tri-
dentata) .

THOMOMYS BOTTAE PLANIHOSTRIS Bubt

Zion Park Pocket Gopher

Thomomys pcrpallidus planirostris Burt, Biol. Soc. Wash. Proc. 44: 38, May
8, 1931.

Type. — From Zion National Park, Utah (altitude 4,400 feet) ;
collected by A. Brazier Howell, May 4, 1920.

General characters. — Size medium but form robust ; colors rich,
the upper parts distinctly tawny, little modified by dark-tipped
hairs. Allied to absonus of House Rock Valley, but colors bright-
er, more tawny, and proportions heavier ; skull more massive, with
heavier dentition.

Measurements (from Burt) . — Average of eight adult male topo-
types: Total length, 238.3 (222-261); tail, 75.6 (66-83); hind
foot, 32.4 (31-34) millimeters. Average of eight adult female topo-
types: 215 (205-228) ; 71 (61-78) ; 30.9 (30-33) millimeters.

Distribution and habitat. — The Zion Park pocket gopher is found
at 4,500 feet on the broad Upper Sonoran, Atriplex overgrown, ter-

THE POCKET GOPHERS 9

race near Fredonia and the vicinity of Kanab Wash to westward.
This brightly colored subspecies apparently ranges into Arizona
through the Short Creek Valley along the western and southern
base of the Vermilion Cliffs west of Fredonia. The burrows in
sandy soil were noted at intervals for miles west of Fredonia.
While planirost?is and absonus occur at points not far apart, and
might be expected to meet along Johnson Creek east of Fredonia,
these animals are very local in distribution and may not be in di-
rect contact. Both forms occur in Zion National Park, but their
ranges in the park appear to be completely separated. The floor
of the narrow valley, at 4,400 feet altitude, in the park, is the type
locality of planirostris, while absonus is found at 5,500 to 5,700
feet in the heads of small canyons and on the plateau near the
east entrance above the barrier formed by the escarpment or east-
ern wall of the valley. At Fredonia pocket gophers enter alfalfa
fields, but are not sufficiently numerous to be very destructive.

THOMOMYS BOTTAE TRUMBULLENSIS Hall and Davis

Mount Trumbull Pocket Gophee

Thomomys bottac trumbullcnsis Hall and Davis, Biol. Soc. Wash. Proc. 47:
51, February 9, 1934.

Type. — From 3 miles south of Nixon Spring, Mount Trumbull,
Mohave County, Ariz, (altitude 6,500 feet) ; collected by Seth B.
Benson, May 26, 1933.

General characters. — A dark-colored lava-area-inhabiting sub-
species. Upper parts normally between cinnamon and cinnamon-
buff, usually rather heavily mixed with black. Of 38 specimens
examined, 7 are deep glossy black, except the feet and the tip of
the tail, which are white. Similar to nicholi of the closely adjoin-
ing, but lower, Shivwits Plateau, and to absonus of House Rock
Valley, but color darker than either, the upper parts more heavily
mixed with black. Compared with planirostris, typical in Zion
National Park, Utah, but which also occurs at Fredonia, Ariz.,
tr-umbullensis is smaller and darker, the upper parts more exten-
sively mixed with black, less tawny; skull slenderer, with lighter
dentition.

Measurements. — Average of three adult male topotypes : Total
length, 234 (228-238) ; tail, 76 (71-83) ; hind foot, 30.5 (30-31)
millimeters. Two adult female topotypes, respectively : 210, 204 ;
68, 56 ; 28, 26.5 millimeters.

Distribution and habitat. — The range of this subspecies is the
lava and cinder area centered about Mount Trumbull on the pla-
teau near the north rim of the Grand Canyon. The area lies
mainly along the boundary between the Upper Sonoran and Tran-

10 NORTH AMERICAN FAUNA 59, FISH AND WILDLIFE SERVICE

sition Zones at 6,000 to 6,500 feet, but extends up to 7,000 feet
on the slopes of Mount Trumbull and Mount Logan, and burrows
were observed at about 4,500 feet altitude on the prominent cinder
cone at the lower end of Toroweap Valley. As pointed out by Hall
and Davis (op. cit. : 52), the darker color of this subspecies, com-
pared with the neighboring geographic races, may indicate a re-
sponse to environmental conditions.

THOMOMYS BOTTAE ABSONUS Goldman

House Rock Valley Pocket Gopher

Thomomys perpallidm absonus Goldman, Jour. Wash. Acad. Sci. 21 (17) : 42">,
October 19, 1931.

Type. — From Jacobs Pools, House Rock Valley, Coconino Coun-
ty, northern Arizona (altitude 4,000 feet) ; collected by E. A.
Goldman, June 7, 1931.

General characters. — A dull grayish buffy subspecies of me-
dium size with a narrow, slender skull. Closely allied to planiro-
stris of Zion National Park, Utah, and the vicinity of Fredonia,
Ariz., but somewhat slenderer, less tawny, and skull less massive.

Measurements. — Average of three adult male topotypes: Total
length, 231 (228-234) ; tail, 77 (74-82) ; hind foot, 31 (30-32.5)
millimeters. Two adult female topotypes, respectively : 210, 217 ;
69, 70 ; 30, 29 millimeters.

Distribution and habitat. — The range of absonus in Arizona is
probably restricted to House Rock Valley, but extends north in
Utah to the eastern entrance of Zion National Park, at 5,700 feet
altitude.

House Rock Valley occupies a broad depression with a gener-
ally level bottom lying in the Upper Sonoran Zone along the north-
ern side of the Marble Canyon of the Colorado River. This reach
of the river bisects the interior basin of which House Rock Val-
ley is the northern half, above the upper entrance to the Grand
Canyon, and forms a barrier limiting the distribution of this sub-
species and of most of the other mammals of the region. The
bottom of House Rock Valley is gashed by side canyons of the
Colorado, and the dispersal of this pocket gopher is much re-
stricted even here. It has been found inhabiting soft sand extend-
ing for several miles out over the floor of the valley from Jacobs
Pools, a spring at the western base of the escarpment marking
the great fault line known as the Vermilion Cliffs. Burrows are
common along the highway through low-growing shrubby vege-
tation, largely Atriplex bushes and Coleogyne ramossissima, a
dominant species on poor soils. But the pocket gophers feed to

THE POCKET GOPHERS 11

a considerable extent on the roots and tender growing tops of the
large white poppy (Argemone).

THOMOMYS BOTTAE AUREUS Allen

Painted Desert Pocket Gopher

Thomomys aureus Allen, Araer. Mus. Nat. Hist. Bull. 5 : 49, April 28, 1S93.
Thomomys latirostris Merriam, Proc. Biol. Soc. Wash. 14: 107, July 19, 1901.

Type from Tanner Crossing, about 3 miles above Cameron, Little Colorado

River, Coconino County, Ariz.

Type. — From Bluff, San Juan County, Utah; collected by
Charles P. Rowley, May 12, 1892.

General characters. — A large, cinnamon-buff or golden-colored
subspecies. Closely allied to and probably intergrading with per-
amplus of the higher mountains of the northeast corner of Ari-
zona.

Measurements. — Average of four adult male topotypes: Total
length, 241 (232-252) ; tail, 73 (69-80) ; hind foot, 31 (30-32) milli-
meters. Average of four adult female topotypes: 222 (215-229) ;
66 (64-72; 30 (30-31) millimeters.

Distribution and habitat. — The range of aureus extends from
the San Juan Valley, Utah, into northeastern Arizona, along the
valley of Chin Lee Creek, and embraces as a whole the major part
of the Painted Desert region to the Little Colorado River. Over
this area, however, the pocket gophers are very irregularly dis-
tributed in more or less isolated colonies that favor the more fer-
tile ground, usually in the valleys, in the Upper Sonoran Zone.
Specimens have been obtained at localities varying in altitude
from about 4,000 feet along the Little Colorado River to 6,500
feet in the Pueblo Colorado Valley at Ganado. The dominant veg-
etation of the region occupied consists largely of Atriplex bushes
or sagebrush {Artemisia tridentata), with a scattered growth
of nut pines and junipers along the valley borders. Thomomys
latirostris was based on a single specimen from Tanner Crossing,
near Cameron, on the Little Colorado River. Efforts to obtain
topotypes, made by various collectors including the writer, have
been unsuccessful. The locality is a very barren one, made more
so by overgrazing by domestic stock in recent years, and if pocket
gophers still occur they must be rare as we found no trace of
them. The skull of the type specimen of latirostris, an old male,
has a very broad rostral portion and is believed to be abnormal,
as no such character appears in specimens from Tuba City, Wins-
low, and Oraibi, which are in the same general faunal area. Be-
tween the range of aureus along the valley of the Little Colorado
River and that of the widely different subspecies fulvus of the

12 NORTH AMERICAN FAUNA 59, FISH AND WILDLIFE SERVICE

Mogollon Plateau is an arid belt in which pocket gophers have not
been detected.

THOMOMYS BOTTAE PERAMPLUS Goldman

Tunitcha Mountain Pocket Gopher

Thomomys fulvus peramplus Goldman, Jour. Wash. Acad. Sci. 21 (17): 423,
October 19, 1931.

Type. — From Wheatfields Creek, west slope of Tunitcha Moun-
tains, Apache County, northeastern Arizona (altitude 7,000 feet) ;
collected by Paul Trapier, June 23, 1927.

General characters. — A large, dark-colored subspecies, closely
resembling apache of northern New Mexico, but upper parts dull-
er, the sides vinaceous-buff instead of ochraceous-buff ; skull more
elongated; nasals longer and broader, less wedge-shaped poste-
riorly. Contrasting strongly with the lighter cinnamon or cinna-
mon-buff tones of aureus, which inhabits parts of the neighbor-
ing desert region, in dark, dull coloration, but cranial characters
indicate close relationship and the two probably intergrade in
places along the basal slopes of the mountains.

Measurements. — Average of four adult male topotypes: Total
length, 246 (240-255) ; tail, 80 (60-90) ; hind foot, 35 (34-37)
millimeters. Average of six adult female topotypes : 230 (225-240) ;
75 (65-88) ; 32 (31-33) millimeters.

Distribution xmd habitat — The Tunitcha Mountain pocket go-
pher is known from 7,000 feet altitude on Wheatfields Creek up
to 8,000 feet on the upper slope of the range. It also occurs at
7,000 feet altitude in the valley at St. Michaels on the eastern
side of the Defiance Plateau. This pocket gopher probably occurs
irregularly in suitable places throughout this high mountainous
section of the State. It gives way, however, at the higher eleva-
tions in the Tunitcha Mountains to Thomomys talpoides fossor,
which tends toward chestnut color, with large, conspicuous, black
ear patches. The general habitat of peramplus is in the yellow
pine belt of the Transition Zone.

THOMOMYS BOTTAE DESERTORTJM Merriam

Detrital Valley Pocket Gopher

Thomomys desertorum Merriam, Biol. Soc. Wash. Proc. 14: 114, July 19. 1901.

Type. — From Mud Spring, Detrital Valley, Mohave County,
Ariz. ; collected by Vernon Bailey, February 21, 1889.

General characters. — A small, tawny subspecies, similar in color
and closely allied to desitus of the Big Sandy River Valley, but
smaller.

Measurements. — An adult male: Total length, 200; tail verte-

THE POCKET GOPHERS 13

brae, 68 ; hind foot, 26 millimeters. Average of four females : 190 ;
60 ; 25.5 millimeters'.

Distribution and habitat. — This little pocket gopher occupies
the Lower Sonoran desert region of the broad Detrital Valley and
neighboring areas lying mainly at about 3,500 feet altitude in the
angle" formed by the bend of the Colorado River north and west
of the Hualpai Mountains in the northwestern part of the State.
It ranges to a somewhat higher elevation in the Upper Sonoran
Zone, however, near its southern limit in the Chemehuevis or Mo-
have Mountains. East of the northern end of the Hualpai Moun-
tains it doubtless intergrades with desitus. The burrows are lo-
cated in hard upland soil among tree yuccas and a varied assort-
ment of other desert vegetation, including cactuses.

THOMOMYS BOTTAE FULVUS (Woodhouse)

Fulvous Pocket Gophek

Geomys fulvus Woodhouse, Acad. Nat. Sci. Phila. Proc. 6: 201, 1852.

Thomomys bottae nasntus Hall, Biol. Soc. Wash. Proc. 45: 96, June 21, 1932.

Type from West Fork of Black River, Apache County, Ariz, (altitude 7,550

feet); collected by Annie M. Alexander, June 14, 1931.

Type. — From San Francisco Mountains, Coconino County,
Ariz. ; collected by S. W. Woodhouse, October 1851.

General characters. — Pocket gophers of medium size, distin-
guished in the region south of the Grand Canyon by dark, rusty
brown coloration associated with that of the dark lava soil they
inhabit. Skull with wide-spreading zygomata and small auditory
bullae. Closely allied to mutabilis of the Verde Valley, but dark-
er, the upper parts more extensively mixed with black; skull less
massive ; basicranial region narrower ; auditory bullae smaller.

Measurements. — Average of five males : Total length, 219 ; tail
vertebrae, 70 ; hind foot, 30 millimeters. Average of five females :
209 ; 66 ; 29.2 millimeters.

Distribution and habitat. — The fulvous pocket gopher is the
most widely dispersed of the numerous representatives of the
Thomomys bottae group found within the State. Its distribution
area occupies the whole of the elevated Coconino and Mogollon
Plateau regions, extending from the southern rim of the Grand
Canyon southeastward to the White Mountains and on far into
New Mexico. A spur from the main range reaches south through
the high country to the Bradshaw Mountains west of the Verde
River Valley. This pocket gopher ranges mainly in the yellow
pine forests of the Transition Zone above 5,000 feet altitude, but
ascends into the Canadian Zone on San Francisco Mountains and
the White Mountains. The general region is marked by cinder

14 NORTH AMERICAN FAUNA 59, FISH AND WILDLIFE SERVICE.

cones and old lava beds, indicating volcanic activity in the past.
The decomposing cinders and lava produce dark-colored soils that
are reflected in the color tones not only of the pocket gophers but
of many of the other small mammals. Along the southern side of
the Mogollon Plateau fulvus • intergrades with mutabilis, which
ranges at lower levels. On the long gradual desert slope from the
top of the plateau toward the Little Colorado River pocket gophers
are generally absent, and no direct connection with aureus, which
inhabits parts of the Little Colorado Valley and Painted Desert,
is apparent.

In the yellow pine forests the pocket gophers occur irregularly
in colonies wherever there is sufficient soil for their excavations,
but they favor the soft soil of open grassy meadows.

THOMOMYS BOTTAE HUALPAIENSIS Goldman

Hualpai Mountains Pocket Gophee

Thomomys bottae hualpaiensis Goldman, Jour. Wash. Acad. Sci. 26 (3) : 114,
March 15, 1936.

Type. — From Hualpai Peak, Hualpai Mountains, Mohave Coun-
ty, Ariz, (altitude 7,000 feet) ; collected by E. A. Goldman, Oc-
tober 6, 1917.

General characters. — A light ochraceous buffy subspecies of
medium size. Allied to desitus of the adjoining valley of the Big
Sandy River; similar in size but paler; brain case lower, nasals
more wedge-shaped. Compared with desertorum of the Detrital
Valley : considerably larger and paler.

Measurements. — The type, an adult male : Total length, 245 ;
tail, 78 ; hind foot, 31.5 millimeters.

Distribution and habitat. — Known only from 6,500 to about
7,500 feet altitude in the Transition Zone on the slopes of the
Hualpai Mountains. The burrows occur in soft spots in yellow
pine and oak timber.

THOMOMYS BOTTAE DESITUS Goldman

Big Sandy Rivek Pocket Gophek

Thomomys bottae desitus Goldman, Jour. Wash. Acad. Sci. 2H (3) : 113, March
15, 1936.

Type. — From Big Sandy River, near Owen, Mohave County,
Ariz, (altitude 2,000 feet) ; collected by E. A. Goldman, Septem-
ber 21, 1917.

General characters. — A medium-sized, tawny subspecies ; color
about as in desertorum of the neighboring Detrital Valley region,
but size much larger. Size about as in fulvus of the Mogollon Pla-

THE POCKET GOPHERS 15

teau, but color lighter, clearer tawny, the back less mixed with
black.

Measurements, — An adult male : Total length, 230 ; tail verte-
brae, 70 ; hind foot, 30.5 millimeters. An adult female : 210 ; 62 ;
29.5 millimeters.

Distribution and habitat. — This pocket gopher occupies the Big
Sandy River Valley. Thence it ranges east to Kirkland, Yavapai
County. Its distribution area is in the Lower Sonoran Zone at
2,000 to 4,000 feet altitude. In the Big Sandy River Valley desitus
is confined mainly to the loose sand along the broad alluvial river
bottom, the excavated mounds of earth often appearing close to
the edge of the water where the stream is bordered by willows
and Baccharis bushes.

THOMOMYS BOTTAE OPEROSUS Hatfield
Peeples Valley Pocket Gophee

Thomomys hottae operosus Hatfield, Chicago Acad. Sci. Bull. 6 (8) : 151, Jan-
uary 12, 1942.

Type. — From Peeples Valley, 6 miles north of Yarnell, Yavapai
County, Ariz, (altitude 4,400 feet) ; collected by Roy Komarek,
May 30, 1937.

General characters. — From original description : Size large ; tips
of hairs on back cinnamon to middorsal area which is blackish;
sides pinkish buff ; top of head blackish ; ears surrounded by
black ; skull broad, with widely spreading zygomata. Differs from
fulvus in larger size, more widely spreading zygomata, greater
mastoid breadth, and heavier dentition. Differs from mutabilis
in darker color, with more black on nose, occiput, and back. Dif-
fers from patulus and desitus in darker color, longer tail, and
more widely spreading zygomata.

Measurements. — From original description: Average of three
adult males: Total length, 232.3 (228-237); tail, 81.3 (80-82);
hind foot, 29 millimeters. Average of eight adult females: 216.5
(202-234) ; 71.4 (65-79) ; 27.4 (26-29) millimeters.

Distribution and habitat. — No specimens of this subspecies have
been examined by the writer. It is known only from the type lo-
cality and appears to be a local race, perhaps restricted to Peeples
Valley, which is somewhat isolated, midway between the desert
country of southern Arizona and the high plateau to the north-
ward.

THOMOMYS BOTTAE CHUYSOXOTUS Grinnell
Golden Pocket Gopher

Thomomys chrysonotus Grinnell, Univ. Calif. Pub. Zool. 10: 174, June 7, 1912.

Thomomys fulvus flavidus Goldman, .lour. Wash. Acad. Sci. 21 (17) : 417,

October 19, 1931. Type from Parker, Yuma County, Ariz, (altitude 350 fefel )

696493°— 47— 3

16 NORTH AMERICAN FAUNA 59, FISH AND WILDLIFE SERVICE

Type. — From Ehrenberg, Yuma County, Ariz. ; collected by
Frank Stephens, March 27, 1910.

General characters. — A large ochraceous-buff or golden yellow-
ish subspecies with an angular massive skull. Similar to albutus,
but upper parts ochraceous-buff instead of pinkish buff; skulls
much alike ; auditory bullae larger, more inflated in chrysonotus.

Measurements. — An adult male : Total length, 249 ; tail verte-
brae, 83 ; hind foot, 33 millimeters. An adult female : 224 ; 67 ;
31.5 millimeters.

Distribution and habitat. — The golden pocket gopher occupies
the alluvial bottomlands along the east side of the Colorado River
from near Ehrenberg north to Parker, and invades the adjoining
gravelly mesa overgrown with creosotebush (Covillea glutinosa)
to some extent. The opposite, or western, side of the Colorado
River Valley is inhabited by Thomomys bottae riparius, the river
serving as a barrier between the two forms. Within the main
range of the golden pocket gopher on the bottomlands the bur-
rows are numerous in the soft alluvial soil and extend down in
places into the arrowweed (Pluchea sericea) belt near the edge
of the water.

THOMOMYS BOTTAE SUBSIMILIS Goldman

Harquahala Mountain Pocket Gopher

Thomomys fulvus suosimilis Goldman, Biol. Soc. Wash. Proc. 46: 71, April
27, 1933.

Type. — From Harquahala Mountains, Yuma County, Ariz, (al-
titude 3,000 feet) ; collected by E. A. Goldman, October 14, 1917.

General characters. — A very small cinnamon-buff animal with
a weakly developed skull. Similar to desertorum of the Detrital
Valley region, but still smaller and paler; skull more delicate in
structure.

Measurements. — The type, an adult female : Total length, 186 ;
tail vertebrae, 60 ; hind foot, 25 millimeters.

Distribution and habitat. — This tiny pocket gopher is known
only from a single specimen from 3,000 feet altitude in the Har-
quahala Mountains. The mountain slopes are rocky, with little
soil, but the animal is likely to be found in the softer spots up to
near the summit at about 5,000 feet altitude. The mountains are
Lower Sonoran in faunal character up to near the top, where a
few Upper Sonoran Zone elements appear.

THOMOMYS BOTTAE PATULUS Goidman

Hassayampa Valley Pocket Gopher

Thomomys bottae patulus Goldman, Jour. Wash. Acad. Sci. 28 (7): 341, Jul)'
15, 1938.

THE POCKET GOPHERS 17

Type. — Prom bottomland along Hassayampa River, 2 miles be-
low Wickenburg, Maricopa County, Ariz., (altitude 2,000 feet) ;
collected by Luther C. Goldman, September 16, 1937.

General characters. — A large subspecies, similar to cervinus of
the Salt River Valley, but upper parts more vivid in color, near
cinnamon or cinnamon-buff instead of vinaceous-buff or fawn;
skull shorter, less angular. Somewhat resembling mutabilis of
the Verde River Valley and desitus of the Big Sandy River Valley,
but larger and paler than either.

Measurements. — An adult male and an adult female topotype,
respectively: Total length, 240, 215; tail, 80, 60; hind foot, 31,
29 millimeters.

Distribution and habitat. — Known only from the type locality,
but probably has an extensive range in alluvial soil along the val-
ley of the Hassayampa River. The subspecies patulus is abun-
dant in alfalfa fields, where it becomes somewhat troublesome to
farmers. The distribution of pocket gophers appears to be dis-
continuous in the arid areas bordering the Hassayampa River
Valley.

THOMOMYS BOTTAK MUTABILIS Goldman

Verde Valley Pocket Gopher

Thomomys fulvus mutabilis Goldman, Biol. Soc. Wash. Proc. 4(i: 75, April
27, 1933.

Type. — From Camp Verde, Yavapai County, Ariz, (altitude
3,200 feet) ; collected by Walter P. Taylor, July 25, 1916.

General characters. — A medium-sized, cinnamon-buff subspecies.
Closely allied to fulvus, but paler, the upper parts less mixed with
black; skull more massive; basicranial region broader; auditory
bullae larger.

Measurements. — An adult male : Total length, 236 ; tail verte-
brae, 71 ; hind foot, 31 millimeters. Average of 7 adult females :
216 ; 68 ; 29 millimeters.

Distribution and habitat. — The Verde Valley pocket gopher in-
habits the valleys and lower slopes of the mountains in the Verde
and Salt River drainages along the southern side of the Mogollon
Plateau from Camp Verde east to the Gila Mountains, Graham
County. Vertical range from about 2,500 to 4,500 feet. This sub-
species inhabiting a region arid in general character favors the
softer soils along streams.

THOMOMYS BOTTAE CERVINUS Allen

Fawn-colored Pocket Gopher; Phoenix Pocket Gopher

TK&momys cervinus Allen, Amer. Mas. Nat Hist. Bull. 7: 208, Jump 2!), lS!>r>.

18 NORTH AMERICAN FAUNA 59, FISH AND WILDLIFE SERVICE

Type. — From Phoenix, Maricopa County, Ariz, (altitude 1,000
feet) ; collected by J. Diefenbach, October 20, 1894.

General characters. — A large vinaceous-buff or light fawn-col-
ored subspecies. Similar to albatus of the lower Colorado River
Valley, but larger; color darker (upper parts near pale pinkish
buff or pinkish buff in albatus) ; skull more elongated, with rela-
tively narrower brain case ; auditory bullae relatively larger. Al-
lied to modicus of the Altar and Santa Cruz Valleys, but larger ;
color paler (near wood brown, varying to tawny in modicus) ;,
skull of similar proportions, but much larger, more massive.

Measurements. — Average of three adult male topotypes: Total
length, 253 (251-255) ; tail, 84 (77-90) ; hind foot, 34.5 (34-36)
millimeters. Average of three adult female topotypes: 246 (239-
255) ; 78 (73-81) ; 34 (33-34.5) millimeters.

Distribution and habitat. — The range of this large pocket go-
pher is in the Salt River and Gila River Valleys, near Phoenix, and'
southwest along the latter watercourse to Gila Bend, where it in-
tergrades with the desert subspecies, aridicola. The general area
is in the Lower Sonoran Zone at from 700 to 1,000 feet altitude..
The fawn-colored pocket gopher is associated with such native'
vegetation as the mesquite (Prosopis juliflora), catsclaw (Aca-
cia greggii), and paloverde (Cercidium torreyanum), but with
the rapid development of agriculture it has invaded the fields and
multiplied greatly in numbers. Owing to the extent of its depre-
dations in an important agricultural area, this pocket gopher
should probably be rated as the most destructive of the numerous
geographic races that occur within the State.

THOMOMYS BOTTAE PINALENSIS Goldman
Pinal Mountains Pocket Gopher

Thomomys bottae pinalensis Goldman, Jour. Wash. Acad. Sci. 28 (7): 342,
July 15, 1938.

Type. — From Oak Flat, 5 miles east of Superior, Pinal Moun-
tains, Ariz. ; collected by Walter P. Taylor, May 22, 1924.

General characters. — A very small cinnamon subspecies, with
a narrow, slenderly formed skull. Most closely allied to mutabilis
of the adjoining region to the north, but much smaller and dark-
er ; skull smaller, narrower, less massive.

Measurements. — The type, an adult female : Total length, 195 ;
tail, 56 ; hind foot, 24 millimeters.

Distribution and habitat. — The burrows of this small subspecies
were noted in numbers in various places along the highway be-
tween Superior and Globe across the upper slopes of the Pinal

THE POCKET GOPHERS 19

Mountains. The animal favors the softer soil in small openings in
the oak woods of the Upper Sonoran Zone.

THOMOMYS BOTTAE ALIENUS Goldman
Upper Gila Valley Pocket Gopher

Thomomys bottae alienus Goldman, Jour. Wash. Acad. Sci. 28 (7): 338, July
15, 1938.

Type. — From Mammoth, San Pedro River, Pinal County, Ariz.
(altitude 2,400 feet) ; collected by E. A. Goldman, November 4,
1936.

General characters. — A large, rich rufescent subspecies, allied
to cervinus of the Salt River Valley, but smaller ; upper parts near
cinnamon instead of vinaceous-buff. Similar to toltecus of the
Casas Grandes Valley, northwestern Chihuahua, but color more
vivid ; skull with lower brain case ; upper incisors less projecting
forward. Larger, less distinctly tawny than mutabilis of the Rio
Verde and Salt River drainages.

Measurements. — Average of four adult male topotypes: Total
length, 240 (230-254) ; tail, 68 (58-80) ; hind foot, 32 (30-33.5)
millimeters. Average of four adult female topotypes: 212 (207-
218) ; 58 (57-59) ; 28 (27.5-28.5) millimeters.

Distribution and habitat. — The general range of this large sub-
species is along the bottoms of the lower San Pedro River Valley
near Mammoth, and the bottoms of the Gila River Valley above
the confluence of the Gila and San Pedro as far as Redrock, New
Mex. The area is in the Lower Sonoran Zone from about 2,000 to
3,500 feet or a little more in altitude. These pocket gophers are re-
stricted rather closely to the fertile, alluvial lands along the rivers,
overgrown in the natural state with a heavy stand of mesquite
(Prosopis juliflora) timber.

Economic status. — Much of the alluvial land along the San Pe-
dro and Gila Rivers is cultivated under irrigation, alfalfa being
one of the principal crops. The pocket gophers feed upon both the
roots and tops of alfalfa and tend to increase in number where
a bountiful supply of food is thus provided. Where they become
very numerous the alfalfa crop is materially reduced. At Safford
the farmers complained of damages to alfalfa, and also of breaks
in irrigation ditchbanks caused by gopher tunneling.

THOMOMYS BOTTAE ALBATUS Grinnell
Whitish Pocket Gopher
Thomomys albatus Grinnell, Univ. Calif. Pub. Zool. 10: 172, June 7, 1912.

Type. — From west side of the Colorado River at old Hanlon
Ranch near Pilot Knob, Imperial County, Calif. ; collected by Jo-
seph Dixon, May 7, 1910.

20 NORTH AMERICAN FAUNA 59, FISH AND WILDLIFE SERVICE

General characters. — Distinguished by extremely pallid color-
ation and rather large size. Upper parts nearly uniform pale pink-
ish buff, in some specimens appearing almost white. Closely al-
lied to phasma of the Tule Desert region, but larger; skull more
massive.

Measurements. — An adult male: Total length, 272; tail verte-
brae, 100; hind foot, 35 millimeters. An adult female: 264; 91;
34 millimeters.

Distribution and habitat. — This nearly white subspecies inhab-
its both sides of the lower Colorado River Valley from the vicin-
ity of Yuma, at least, to points in the Delta. It burrows in soft
alluvial soil, and local occurrence points to the transfer of colonies
from one side to the other with the frequently changing channels
of the river. Across the lowlands of the Delta, therefore, the gen-
eral range of albatus appears to be the connecting link in a chain
of subspecies of the Thomomys bottae group extending from the
Pacific coast to the Rio Grande Valley in Texas.

THOMOMYS BOTTAE DEPAUPERATUS Grinnell and Hill

Tinajas Altas Pocket Gopher

Thomomys perpallidus depauperatus Grinnell and Hill, Jour. Mammal. 17 (1):
4, February 17, 1936.

Type. — From the east base of the Tinajas Altas Mountains, 7
miles south of Raven Butte, Yuma County, Ariz, (altitude 1,150
feet) ; collected by Annie M. Alexander, January 17, 1934.

General characters. — Distinguished by pale pinkish buff colora-
tion combined with small size. Color about as in the geographic
neighbors albatus and phasma, but smaller than either (much
smaller than albatus) ; skull weaker in structure, less angular
than in phasma; zygomata more slender; nasals relatively shorter.

Measurements. — A representative female (from original de-
scription) : Total length, 188; tail, 60; hind foot, 28 millimeters.

Distribution and habitat. — Known only from a small colony in
the desert along the eastern base of the Tinajas Altas Mountains,
a southern extension of the Gila Mountains, and about 4 to 5 miles
north of the Mexican Boundary. It is reported to inhabit gravel-
ly soil along the margins of washes, where the mesquite (Prosopis
juliflora) and catsclaw {Acacia greggii) are among the dominant
woody plants.

THOMOMYS BOTTAE PHASMA Goldman

Tule Desert Pocket Gopher

Thomomys fulvus phasma Goldman, Biol. Soc. Wash. Proc. 46: 72, April 27, 1933.

Type. — From 2 miles south of Tule Tank, Tule Desert, Yuma

THE POCKET GOPHERS 21

County, Ariz, (altitude 1,200 feet) ; collected by E. A. Goldman,
December 8, 1913.

General characters. — One of the palest of the known forms of
the genus. Upper parts near pale pinkish buff, scarcely modified
by dark-tipped hairs. Closely allied to ulbatus of the Colorado
Delta region, but smaller; skull less massive.

Measurements. — An adult female: Total length, 199; tail verte-
brae, 66; hind foot, 29 millimeters.

Distribution and habitat. — The Tule Desert pocket gopher oc-
curs irregularly so far as known in small, local colonies on the
low Lower Sonoran plains from the vicinity of the type locality
near the Mexican Boundary northwest to Wellton, Yuma County.
Its habitat on the desert is in one of the most arid regions in North
America. The burrows are found along washes and in open stands
of desert vegetation, including the creosotebush (Covillea triden-
tata), ironwood (Olneya tesota), paloverde (Cercidium torreya-
num), and giant cactus (Carnegiea. gigantea) . Numerous mounds
of earth pushed out near together at about the same time are evi-
dences of periodical activity, apparently following rains, which
are infrequent in the region. Periodical excavation of earth on
an extensive scale is a characteristic of pocket gophers in general
that seems emphasized in this and some of the other desert forms.
During the long intervals between rains the animals remain in the
deeper underground workings, and there is little evidence of activ-
ity on or near the surface. At such times tunnels near the surface
are generally plugged for several feet, or show signs of disuse.
To obtain specimens of the gophers may involve considerable la-
bor, as under such conditions it may be necessary to dig a trench
2 to 3 feet deep with a shovel in order to reach the used tunnels
where traps can be set with excellent results.

THOMOMYS BOTTAE ARIOICOLA Huey

Gila Bend Pocket Gopher

Thomomys bottae aridicola Huey, San Diego Soc. Nat. Hist. Trans. 8 (25):
354, June 15, 1937.

Type. — From 10 miles south of Gila Bend (or, exactly, on Ajo
Railroad right-of-way, about 2 miles north of Black Gap), Mari-
copa County, Ariz, (altitude 900 feet) ; collected by Laurence M.
Huey, February 1, 1936.

General characters. — A medium-sized, light buffy, desert sub-
species. Similar to cervinus of the Salt River Valley, but smaller
and color of upper parts shading toward cinnamon-buff instead
of vinaceous-buff.

Measurements. — Type, an adult female: Total length, 212; tail,
63 ; hind foot, 29 millimeters.

22 NORTH AMERICAN FAUNA 59, FISH AND WILDLIFE SERVICE

Distribution and habitat. — The type and a topotype of this pock-
et gopher came from close along the Ajo Railroad, 2 miles north of
Black Gap, and 10 miles south of Gila Bend, Maricopa County,
Ariz. The animal appears to be one of the isolated forms that
exist as local colonies in the wide expanse of Lower Sonoran des-
ert.

THOMOMYS BOTTAE GROWLERENSIS Huey

Growler Valley Pocket Gopher

Thomomys bottae grmvlerensis Huey, San Diego Soc. Nat. Hist. Trans. 8 (25) :
353, June 15, 1037.

Type. — From 7 miles east of Papago Well, Pima County, Ariz.
( or, exactly, along a well wooded desert wash on the southwestern
side of a range of hills in the southern end of Growler Valley ; the
Agua Dulce Mountains form the southern boundary of this local-
ity and are not far distant) ; collected by Laurence M. Huey,
March 16, 1937.

General characters. — A desert form, closely allied to phxisma
of the Tule Desert to the west, but darker, deeper pinkish buff or
yellowish in color. Much lighter colored in comparison with modi-
cus of the Altar Valley to the east.

Measurements. — Type, an adult male: Total length, 208; tail,
62 ; hind foot, 30 millimeters.

Distribution and habitat. — The known range of this denizen
of the desert includes several localities from the southern end of
Growler Valley and Quitobaquito north to Bates Well in Growler
Pass, between the Growler Mountains and Bates Mountains, all
in the Lower Sonoran Zone. The burrows are usually found in
soft soil along gravelly wooded washes where the ironwood (01-
neya tesota), mesquite (Prosopis) , catsclaw (Acacia greggii), and
paloverde (Cercidium torreyanum) are among the dominant
woody plants.

THOMOMYS BOTTAE COMOBABIENSIS Huey

Comobabi Pocket Gopher

Thomomys bottae comobabiensis Huey, San Diego Soc. Nat. Hist. Trans. 8
(25): 354, June 15, 1937.

Type. — From 5 miles northwest of Sells, Pima County, Ariz,
(altitude 2,400 feet) ; collected by Laurence M. Huey, March 22,
1937.

General characters. — A medium-sized, distinctly brownish sub-
species. Similar in color to modicus of the Altar Valley, but some-
what smaller; skull with larger, more fully inflated, auditory
bullae.

Measurements. — The type, an adult female: Total length, 215;

THE POCKET GOPHERS 23

tail, 70 ; hind foot, 28 millimeters.

Distribution and habitat. — Known only from the type locality
on the basal slope of the Comobabi Mountains. Like some of the
other desert representatives of the genus, this form appears to be
very local in distribution. More abundant material for study may
show close alliance to modicus to which specimens from Sells are
referred.

THOMOMYS BOTTAE PUSILLUS Goldman

Coyote Mountain Pocket Gopher

Thomomys fulvus pusillus Goldman, Jour. Wash. Acad. Sci. 21 (17): 422.
October 19, 1931.

Type. — From Coyote Mountains, Pima County, Ariz, (altitude
3,000 feet) ; collected by E. A. Goldman, September 4, 1915.

General characters. — A small, rich ochraceous-tawny form with
a slender, delicate skull and large, fully distended, auditory bullae.
Mammae, pectoral two pairs, inguinal two pairs. Allied to modi-
cus of the neighboring valleys, but much smaller; color more
tawny.

Measurements. — The type, an adult female : Total length, 201 ;
tail vertebrae, 65 ; hind foot, 27.5 millimeters.

Distribution and habitat. — As the name implies, this is a very
small pocket gopher. It is known only from a spot where a little
soil had accumulated at 3,000 feet altitude in the exceedingly
rocky Coyote Mountains. It is associated with the catsclaw (Aca-
cia greggii), mesquite (Prosopis juliflora), and other vegetation
of the Lower Sonoran Zone.

THOMOMYS BOTTAE GKAHAMENSIS Goldman

Graham Mountains Pocket Gopher

Thomomys fulvus yrahamensis Goldman, Jour. Wash. Acad. Sci. 21 (17) : 420,
October 19, 1931.

Type. — From Graham Mountains (=Pinaleno Mountains), Gra-
ham County, Ariz, (altitude 9,200 feet) ; collected by Ernest G.
Holt, June 7, 1914.

General characters. — A dark, high-mountain subspecies, resem-
bling fulvus of the Mogollon Plateau region, but upper parts near
ochraceous-buff instead of ochraceous-tawny, but as in fulvus
rather heavily mixed with black; skull narrower, with zygomata
less widely spreading. About like collinus of the Chiricahua Moun-
tains in color; skull narrower, but interorbital region broader.

Measurements. — An adult male : Total length, 231 ; tail verte-
brae, 71 ; hind foot, 29 millimeters. An adult female : 228 ; 76 ; 28
millimeters.

696493°— 47— 4

24 NORTH AMERICAN FAUNA 59, FISH AND WILDLIFE SERVICE

Distribution and habitat. — This subspecies is known only from
the forested upper slopes (6,100 to 9,200 feet altitude) of the
Graham Mountains, which like other ranges of the general region,
rise steeply, island-like, from arid surrounding plains and valleys.
This pocket gopher burrows in soft soil in the Transition Zone,
and is numerous in the grassy high mountain meadows bordered
by firs (Pseudotsuga) and spruces (Picea) in the Canadian Zone
along the crest of the range. Pocket gophers from Fort Grant at
the west base are closely allied to graliamensis, but are much paler
and are referred to extenuatus. Along the arid, eastern basal
slopes of the Graham Mountains pocket gophers are scarce or ab-
sent, and grahamensis contrasts strongly with alienus, which is
abundant along the Gila Valley.

THOMOMYS BOTTAE EXTENUATUS Goldman

Sulphur Springs Valley Pocket Gopher

Thomomys bottae extenuatus Goldman, Biol. Soc. Wash. Proc. 48: 149, Oc-
tober 31, 1935.

Type. — From Willcox, Cochise County, Ariz, (altitude 4,000
feet) ; collected by Vernon Bailey, November 27, 1889. .

General characters. — This small cinnamon-buff or light tawny
pocket gopher, with strongly decurved upper incisors and large
auditory bullae, is allied to several neighboring forms from all
of which it differs in combination of size, color, and skull struc-
ture. Similarity in color of extenuatus to alienus of the lower el-
evations along the San Pedro and Gila River Valleys is evident,
but the smaller general size and more swollen auditory bullae of
extenuatus are distinctive. Extenuatus is about the same in size
as, and evidently related to, the neighboring high-mountain forms
grahamensis, collinus, catalinae, and hueyi but differs from
all in lighter color and cranial details. In size and color extenua-
tus closely approaches Thomomys baileyi mearnsi, and the two oc-
cur together in places ; extenuatus may be recognized by the high-
er brain case and heavier dentition, and the upper incisors are
more strongly recurved instead of projecting forward beyond the
nasals as in mearnsi.

. Measurements. — An adult male and an adult female topotype,
respectively: Total length, 203, 198; tail, 67, 67; hind foot, 27.5,
29 millimeters.

Distribution and habitat. — The range of extenuatus embraces
the desert plains and the basal mountain slopes bordering the Sul-
phur Springs Valley, and adjoining valleys near the top of the
Continental Divide, extending east into the San Simon Valley,
north to Fort Grant, and west across the upper part of the San

THE POCKET GOPHERS 25

Pedro Valley to Oracle. The general area lies near the boundary
between the Upper and Lower Sonoran Zones. In this region, as
near Willcox, the ranges of extenuatus and meamsi, which are re-
garded as representatives of distinct species, interdigitate, and
careful examination of skulls may be necessary to distinguish
them.

THOMOMYS BOTTAE CATALINAE Goldman

Santa Catalina Pocket Gopher

Thomomys fulrvs catalinae Goldman, Jour. Wash. Acad. Sci. 21 (17): 419,
October 19, 1931.

Type. — From Summerhaven, Santa Catalina Mountains, Pima
County, Ariz, (altitude 7,500 feet) ; collected by E. A. Goldman,
August 6, 1923.

General characters. — A small, notably dark-colored subspecies,
the upper parts tawny, heavily mixed with black. Closely allied
to hueyi of the Rincon Mountains, but darker in color, the upper
parts more profusely mixed with black, and the under parts hav-
ing a darker buff tone. Closely resembles collinus of the Chirica-
hua Mountains in dark color, but skull flatter and narrower ; zygo-
mata less widely spreading.

Measurements. — Average of four adult male topotypes: Total
length, 211 (204-220) ; tail vertebrae, 64 (58-72) ; hind foot, 28.5
(27.5-30) millimeters. Average of four adult female topotypes:
202 (196-212) ; 59 (55-62) ; 25 (24-26) millimeters.

Distribution and habitat. — This richly colored pocket gopher
is restricted to the upper slopes of the Santa Catalina Mountains,
where it burrows in the soft, gravelly soil in rather open stands of
timber, largely yellow pines and oaks, in the Transition Zone at
7,000 to 8,000 feet altitude. It also occurs, however, among Cana-
dian Zone elements nearer the summit of Mount Lemmon. The
oak belt along the northern basal slope of these mountains, at Or-
acle, is inhabited by pocket gophers obviously closely related to
the present form, but that in color are more like extenuatus, to
which they are referred. The Santa Catalina Mountains are con-
nected across a saddle or pass with the Rincon Mountains, the
upper slopes of which are occupied by the closely related, but pal-
er, form hueyi. Mountainous masses of nearly solid rock tend to
separate the two, and the well marked, small, local form parvulus
is interposed in a series of shallow, rock-bound depressions filled
with stony soil in the pass. Pocket gophers appear to be absent
in a broad, arid belt along the southern side of the Santa Catalina
Mountains, and no evidence of intergradation with modicus,
which is common along the Santa Cruz River near Tucson, is found.

26 NORTH AMERICAN FAUNA 51), FISH AND WILDLIFE SERVICE

THOMOMYS BOTTAE PARVULUS GOLDMAN

Intermountain Pocket Gopher

TJiomomys bottae parvulus Goldman, Jour. Wash. Acad. Sci. 28 (7) : 339,
July 15, 1938.

Type. — From the pass between the Santa Catalina and Rincon
Mountains, Pima County, Ariz, (altitude 4,500 feet) ; collected by
Luther C. Goldman, June 5, 1937.

General characters. — A very small cinnamon or tawny subspe-
cies; mammae, pectoral two pairs, inguinal two pairs. Allied to
catalinue of the upper slopes of the closely adjoining Santa Cata-
lina Mountains, and to hueyi of similar proximity in the Rincon
Mountains, but much smaller than either, color lighter, more in-
clining toward tawny.

Measurements. — Two adult male topotypes, respectively: Total
length, 203, 211 ; tail, 60, 57 ; hind foot, 27, 25 millimeters. Two
adult female topotypes, respectively: 190, 188; 56, 55; 25, 25
millimeters.

Distribution and habitat. — These diminutive pocket gophers are
apparently restricted in range to gravelly pockets in the granitic
formation in the pass between the Santa Catalina and Rincon
Mountains. Here they are numerous, although the soil is so thin
and scanty that gopher excavations consist largely of pebbles.
Massive rock exposures in the vicinity may be effective barriers
limiting distribution. The area, at 4,000 to 4,500 feet altitude, is
near the boundary between the Upper Sonoran and Lower Sono-
ran Zones, as shown by overlapping floral elements. The Upper
Sonoran Zone is represented by the lower edge of the oaks (Quer-
cus arizonica and Q. emoryi), but along these is a thin stand
of mesquite (Prosopis julifloia), catsclaw (Acacia greggii), and
desertwillow (Chilopsis lineaiis).

THOMOMYS BOTTAE HUEYI Goldman

Rincon Mountains Pocket Gopher

Thomomys bottae hueyi Goldman, Jour. Wash. Acad. Sci. 28 (7) : 340, July
15, 1938.

Type. — From Spud Rock Ranger Station, Rincon Mountains,
Pima County, Ariz, (altitude 7,400 feet) ; collected by Laurence
M. Huey, June 17, 1932.

General characters. — A small, cinnamon subspecies, closely al-
lied to catalinae of the adjoining Santa Catalina Mountains, but
upper parts less profusely mixed with black, and under parts a
lighter buff tone. Larger than its near neighbor parvulus, which
occupies the pass between the Rincon Mountains and Santa Cata-
lina Mountains ; color darker, less tawny.

THE POCKET GOPHERS 27

Measurements. — Two adult male topotypes, respectively: Total
length, 220, 220 ; tail, 62, 66 ; hind foot, 30, 29 millimeters. Two
adult female topotypes, respectively: 198, 196; 60, 60; 26, 27 mil-
limeters.

Distribution and habitat. — In the Rincon Mountains hueyi is
known from the Transition Zone near the top at 7,400 to 7,900
feet altitude. Pocket gophers that appear to be referable to this
subspecies are also found at about 7,000 feet altitude in Ramsay
Canyon and in the head of Miller Canyon in the Huachuca Moun-
tains. The same subspecies may inhabit the Whetstone Mountains
and elevated plains between the two localities mentioned. In the
Rincon Mountains massive rock exposures apparently separate the
habitat of hueyi from that of parvulus in the pass connecting this
range with the Santa Catalina Mountains.

THOMOMYS BOTTAE COLLINUS Goldman
Chikicahua Mountain Pocket Gopheb

Thomomys fulvus collinus Goldman, Jour. Wash. Acad. Sci. 21 (17): 421, Oc-
tober 19, 1931.

Thomomys umbrinus chiricahuae Nelson and Goldman, Jour. Mammal. 15 (2):
117, May 15, 1934. Type from Pinery Canyon, Chiricahua Mountains,
Ariz, (altitude 7,500 feet).

Type. — From Fly Park, Chiricahua Mountains, Cochise County,
Ariz, (altitude 9,000 feet) ; collected by A. K. Fisher, June 10,
1894.

General characters. — A dark, high-mountain subspecies, resem-
bling catalinae of the Santa Catalina Mountains and grahamen-
sis of the Graham Mountains, but skull differing in more widely
spreading zygomata and other details. Pectoral mammae, normal-
ly two pairs, but they may vary to one pair.

Measurements. — Average of five adult males : Total length, 213
(207-222) ; tail vertebrae, 58 (50-60) ; hind foot, 28.3 (27-30) mil-
limeters.

Distribution and habitat. — Like some other high-mountain forms
of the general region, this pocket gopher is restricted to a single
mountain range, and in this case the Chiricahua Mountains. It
ranges from the mouths of Cave and Turkey Creeks at about 5,000
feet altitude on the eastern and western sides, respectively, to the
extreme summit of Fly Peak, at 9,700 feet, but is most abundant
in the soft, dark soil of mountain meadows, such as Rustler Park,
at 8,500 feet altitude in the Canadian Zone. Specimens from the
lower elevations are somewhat paler and approach extenuatus of
the Sulphur Springs Valley region. A few specimens from 7,500
feet in Pinery Canyon are small, and as only one pair of pectoral
mammae was found, they were described as Thomomys umbrinus

28 NORTH AMERICAN FAUNA 59, FISH AND WILDLIFE SERVICE

chiricahuae, but the number of these mammae proves to vary from
normal in some individuals. Additional specimens of collinus in-
dicate that the characters ascribed to chiricahuae are within the
range of individual variation in that form.

THOMOMTS BOTTAE MODICUS Goldman

Altar Valley Pocket Gopher

Thomomys fulvus modicus Goldman, Jour. Wash. Acad. Sci. 21 (17): 418,
October 19, 1931.

Type. — From La Osa (near Mexican Boundary), southern end
of Altar Valley, Pima County, Ariz. ; collected by E. A. Mearns
and F. X. Holzner, December 14, 1893.

General characters. — A dark-colored subspecies of medium size.
Closely allied to cervinus of the Salt River Valley, but smaller;
upper parts near wood brown or cinnamon, varying to rich tawny
instead of vinaceous-buff or fawn color ; skull more slender.

Measurements. — Average of four adult male topotypes: Total
length, 214 (204-222) ; tail vertebrae, 67 (55-75) ; hind foot, 28
(25.5-30) millimeters. Average of six female topotypes : 208 (198-
224) ; 69 (60-74) ; 27.5 (26.5-28) millimeters.

Distribution and habitat. — The general range of this subspecies
includes the Altar Valley, the upper part of the Santa Cruz River
Valley, and neighboring valleys and desert plains as far west as
Sells, and east to Fort Huachuca. The altitudinal limits are from
about 2,500 to about 4,500 feet, mainly in the upper part of the
Lower Sonoran Zone. The vegetation consists prominently of
mesquite (Prosopis juliflora), catsclaw (Acacia greggii), palo-
verde (Cercidium torreyanum), creosotebush (Covillea triden-
tata), and many cactuses. The gophers range up in places, how-
ever, along the basal slopes of the mountains into the lower edge of
the oaks (Quercus emoryi and Quercus arizonica), marking the
Upper Sonoran Zone. Distribution, as in many other forms of
the group, is not continuous. These pocket gophers exhibit a pref-
erence for the softer soils along streams and dry washes, which
may be separated by many miles of unoccupied desert. Along the
lower slopes of the Santa Rita and Huachuca Mountains, modicus
meets the range of Thomomys umbrinus proximus, regarded as a
representative of a distinct species.

THOMOMYS ALEXANDRAE Goldman

Navajo Pocket Gopher

Thomomys alexandrae Goldman, Jour. Wash. Acad. Sci. 23 (10): 464, Oc-
tober 15, 1933. ,

Type. — From 5 miles southeast of Rainbow Lodge, near Navajo

THE POCKET GOPHERS 29

Mountain, Coconino County, Ariz, (altitude 6,200 feet) ; collected
by E. A. Goldman, June 16, 1933.

General characters. — An apparently distinct species of the
Thomomys bottae group, allied to aureus of the adjoining desert
region, but decidedly smaller; color much duller, near cinnamon-
buff instead of rich ochraceous-tawny ; skull flatter and slen-
derer, with more widely separated temporal ridges.

Measurements. — An adult male: Total length, 210; tail, 60;
hind foot, 28 millimeters. An adult female: 215; 70; 27 milli-
meters.

Distribution and habitat. — The Navajo pocket gopher is com-
mon in places on the nearly flat sagebrush-covered mesa at 6,200
feet altitude south of Navajo Mountain. It has also been recorded
by Benson (Univ. Calif. Pub. Zool. 40: 449, Dec. 31, 1935) from
near Soldier Spring at 8,600 feet on Navajo Mountain, just across
the Utah line. The species appears to be isolated in a somewhat
triangular area between the precipitous walls of Navajo and Pin-
to Creek canyons which diverge to the Colorado River. Along
the narrow divide between the upper courses of these creeks
the solid bedrock formation is nearly bare of soil for miles. None
of the characteristic gopher mounds was seen, and this barren
ridge, as well as the canyons, may have served as an effective bar-
rier isolating the habitat of alexandrae for thousands of years.

THOMOMYS SUBOLES Goldman

Searchlight Fekry Pocket Gopheb

Thomomys fulvus .wholes Goldman, Biol. Soc. Wash. Proc. 41: 203, December
18, 1928.

Type. — From Old Searchlight Ferry, Colorado River, north-
west of Kingman, Mohave County, Ariz, (altitude 600 feet) ; col-
lected by Luther C. Goldman, September 26, 1923.

General characters. — A small, light-colored species, allied to
desertorum of the Detrital Valley, but more ochraceous-tawny;
skull more angular, narrower, but heavier in detail; maxillary
arms of zygomata much broader, with acutely projecting lateral

angles; auditory bullae more compressed laterally, less rounded.

Measurements. — An adult male: Total length, 227; tail verte-
brae, 75; hind foot, 30 millimeters. An adult female: 194; 62;
26.5 millimeters.

Distribution and habitat. — In an embayment of the escarpment
flanking the Colorado River, near Old Searchlight Ferry, above
Pyramid Canyon, and northwest of Kingman, Ariz., are alluvial
bottoms extending for several miles until interrupted by cliffs

30 NORTH AMERICAN FAUNA 59, FISH AND WILDLIFE SERVICE

rising abruptly from the water. The bottoms, consisting of soft,
sandy soil, are overgrown with mesquite (Prosopis), catsclaw
(Acacia greggii), and other Lower Sonoran Zone vegetation. The
pocket gophers have become isolated here in a narrow belt be-
tween the river and the escarpment, which arises steeply to the
crest of a rocky ridge at about 3,500 feet altitude. These pocket
gophers have evidently found their restricted habitat congenial
as attested by their numbers. The distribution and habitat of sub-
oles in relation to other species have been discussed in detail by
Grinnell and Hill (Jour. Mammal. 17 (1) : 7-10, Feb. 17, 1936),
who refer to the occurrence of a quite different subspecies, Tho-
momys bottae centralis, on the opposite side of the Colorado River,
although the two forms live under similar conditions of soil, cli-
mate, and food.

THOMOMYS MURALIS Goldman

Grand Canyon Pocket Gophkb

Thomomys muralis Goldman, Jour. Wash. Acad. Sci. 26 (3) : 112, March 15,
1936.

Type. — From lower end of Prospect Valley, Grand Canyon,
Hualpai Indian Reservation, Ariz, (altitude 4,500 feet) ; collected
by E. A. Goldman, October 3, 1913.

General characters. — A diminutive ochraceous buffy or some-
what tawny species, similar in size and in color to, and closely
resembling, desertorum, but cranial characters distinctive ; brain
case more rounded and inflated, the basicranial region tending
to bulge more prominently posteriorly; frontal region broader;
upper incisors more strongly recurved. Differs from fulvus in
lighter color, and smaller size, the skull more delicate in structure
and exhibiting a departure in about the same details as from des-
ertorum.

Measurements. — Type, an adult male: Total length, 194; tail,
64; hind foot, 26 millimeters. Two adult female topotypes, re-
spectively: 182, 190; 57, 56; 24.5, 25.5 millimeters.

Distribution and habitat. — Isolated on terraces along the inner
gorge below the outer rim in Prospect Valley, a lateral pocket
within the Grand Canyon, near the eastern end of the Hualpai
Indian Reservation. The geographic isolation of muralis in the
Grand Canyon appears to be complete, and characters presented
suggest full specific rank. In places it was found inhabiting strips
of soil on ledges only a few feet wide, bounded above and below
by vertical cliffs hundreds of feet high. Zonal range : Upper So-
noran.

THE POCKET GOPHERS 31

THOMOMYS HARQUAHALAE Grinnell and Hill

Ranegras Plain Pocket Gopheb

Thomomys harquahalae Grinnell and Hill, Jour. Mammal. 17 (1) : 7, Feb-
ruary 17, 1936.

Type. — From Ranegras Plain, 10 miles west of Hope, Yuma
County, Ariz, (altitude about 1,250 feet) ; collected by Louise
Kellogg, February 27, 1934.

General characters. — A large pinkish buff species; skull with
widely spreading zygomata and anteriorly projecting upper inci-
sors. Not very closely allied to any other known form, and there-
fore accorded full specific status. Similar to chrysonotus of the
Colorado River Valley, but paler (cinnamon-buff in chrysonotus) ;
zygomata wider; upper incisors strongly procumbent instead of
strongly decurved; auditory bullae shorter, more rounded, less
projecting below plane of basioccipital.

Measurements. — An adult male: Total length, 236; tail verte-
brae, 69; hind foot, 31 millimeters. An adult female: 210; 62;
29.5 millimeters.

Distribution and habitat. — Known only from a colony along the
highway where it crosses the lowest part of the broad open grassy
Ranegras Plain west of Hope. The soil in which these pocket
gophers burrow is compact in texture and difficult to perforate,
suggesting a possible special use for the forward-curving incisors.
Many mounds, marking excavations in the highway embankment,
where food appears to be scanty, indicate that the animals wel-
come a change from the hard soil of their natural habitat.

SUBSPECIES OF THOMOMYS BAILEYI GROUP

THOMOMYS BAILEYI JN1EARNSI Bailey
Mearns Pocket Gopher
Thomomys mearnsi Bailey, Biol. Soc. Wash. Proc. 27: 117, July 10. 1914.

Type. — From Gray's Ranch, Animas Valley, southwest corner
of Grant County, N. Mex. ; collected by E. A. Goldman, August
10, 1908.

General characters. — This subspecies, a near relative of typical
baileyi of western Texas, requires close comparison with extenu-
atus, a form of the bottae group in Arizona, as the ranges of the
two meet or interdigitate. In cinnamon-buff or light tawny color-
ation mearnsi resembles extenuatus, and for differential charac-
ters recourse must be had to the skull, which is very similar in
general, but relatively broader with a somewhat lower, flatter
brain case, a combination of characters apparently indicating
group relationship. In mearnsi the dentition is lighter, the upper

32 NORTH AMERICAN FAUNA 59, FISH AND WILDLIFE SERVICE

incisors narrower, more projecting forward beyond the nasals.

Measurements. — Type, adult male, and an adult female topo-
type, respectively : Total length, 220, 201 ; tail, 67, 65 ; hind foot,
31, 29 millimeters.

Distribution and habitat. — The range of mearnsi extends from
the Animas Valley, southwestern New Mexico, into the elevated
plains region mainly in the lower part of the Upper Sonoran Zone
of southeastern Arizona. Specimens were obtained in soft moist
ground along a small stream at San Bernardino, near the Mexican
Boundary and on the open plain near Willcox in the Sulphur
Springs Valley. While mearnsi and extenuatus appear to be typ-
ically quite distinct, their general ranges meet or interdigitate
and specimens from San Simon Valley suggest the possibility of
hybridism. The exact habitat relations of the two forms remain,
therefore, to be determined.

SUBSPECIES OF THOMOMYS TALPOIDES GROUP

THOMOMYS TALPOIDES KAIBABENSIS Goldman

Kaibab Plateau Pocket Gopheb

Thomomys fosaor kaibabensis Goldman, Jour. Wash. Acad. Sci. 28 (7): 333,
July 15, 1938.

Type. — From DeMotte Park, Kaibab Plateau, Ariz, (altitude
9,000 feet) ; collected by Luther C. Goldman, September 10, 1937.

General characters. — Resembles fossor of southwestern Colo-
rado, but larger, less ruf escent ; skull with more widely spreading
zygomata; interparietal smaller; auditory bullae larger; upper
incisors broader, less recurved.

Measurements. — An adult male and an adult female topotype,
respectively: Total length, 238, 230; tail, 58, 77; hind foot, 31, 30
millimeters.

Distribution and habitat. — The Kaibab Plateau pocket gopher
appears to be restricted to the higher parts of the well forested
Kaibab Plateau, which rises island-like from arid plains or broad
valleys toward the north and presents a sheer face alonge the
north side of the deepest part of the Grand Canyon. This pocket
gopher occurs irregularly in local colonies mainly in the Canadian
Zone at 8,500 to 9,000 feet altitude. These animals are numerous
in the soft soil in DeMotte Park near the top of the plateau, an
open grassy meadow several miles in length, bordered by fir,
spruce, and aspen forest. Specimens have also been taken near
the northern rim of the Grand Canyon.

General habits. — In DeMotte Park, on the Kaibab Plateau, when
the deep snow of winter melts away, many lines of earth 5 to 10

THE POCKET GOPHERS 33

feet in length, with branches, are revealed radiating from the en-
trances to the burrows of the gophers. These cylindrical dumps,
in addition to the usual mounds, are evidence of burrowing opera-
tions late in winter that seem to be followed in spring by a period
of comparative inactivity.

THOMOMYS TALPOIDES FOSSOR Allen
Rocky Mountain Pocket Gopher
TKomomys fossor Allen, Amer. Mus. Nat. Hist. Bull. 5: 51, April 28, 1893.

Type. — From Florida, La Plata County, Colo, (altitude 7,200
feet) ; collected by Charles P. Rowley, June 25, 1892.

General characters. — Small pocket gophers, characterized by the

chestnut brown overtone of the top of head and back and con-
spicuous black ear patches; skull (compared with bottae group)
narrow, with widely separated temporal ridges ; interparietal tri-
angular; zygomata depressed posteriorly, the jugal sloping up-
ward to join maxilla anteriorly ; auditory meatus large and promi-
nent.

Measurements. — An adult male and an adult female, respec-
tively, from the Lukachukai Mountains: Total length, 212, 210;
tail, 70, 60 ; hind foot, 30, 28 millimeters.

Distribution and habitat. — The Rocky Mountain pocket gopher
is a denizen of the upper slopes of high mountains. In Arizona
fossor is known only from about 8,000 to 9,000 feet altitude, main-
ly in the Canadian Zone, near the tops of the Tunitcha and Luka-
chukai Mountains in the northeastern corner of the State. Here
its range seems to meet that of Thomomys bottxie peramplus,
which extends from the lower slopes upward to about 8,000 feet,
but the two forms are not known to occupy the same local terrain.

SUBSPECIES OF THOMOMYS UMBRINUS GROUP

THOMOMYS UMBRINUS PROXIMUS Burt and Campbell
Ahivaca Pocket Gopher

Thomomys burti proximus Burt and Campbell, Jour. Mammal. 15 (2): L51,

May 15, 1934.

Type. — From Old Parker Ranch (Pickett's Ranch on U. S.
Geological Survey topographic map, Patagonia Quadrangle, edi-
tion of August 1905) , altitude 4,800 feet, west slope of Santa Rita
Mountains, Pima County, Ariz. ; collected by W. H. Burt, June
9, 1931.

General characters. — A small, pale russet-colored form, similar
to Thomomys umbrinus burti of the upper slopes of the Santa Rita
Mountains. Some specimens are not very unlike Thomomys bottae
modicus of the neighboring plains, representing a distinct species ;

34 NORTH AMERICAN FAUNA 59, FISH AND WILDLIFE SERVICE

pectoral mammae, sometimes two pairs, as in modicus; skull more
slender, with narrower nasals and smaller auditory bullae. Simi-
lar in size to burti, but upper parts paler, less deep russet, with a
less well denned, less uniformly darkened median dorsal area;
skull very similar.

Measurements. — Type, an adult female : Total length, 193 ;
tail, 61 ; hind foot, 25 millimeters. Two adult males, respectively,
from Fort Huachuca : 200, 195 ; 59, 54 ; 27, 26 millimeters.

Distribution and habitat. — A few specimens have been taken
at the type locality on the west slope of the Santa Rita Mountains,
at the Empire Ranch, east of these mountains, at Fort Huachuca,
and at Arivaca. At Arivaca, W. P. Taylor collected two specimens
on the same day, one of which is referred to proximus and the
other to typical modicus, a representative of a species regarded
as distinct. Of 20 specimens from the Empire Ranch, 19 are nearly
typical modicus, but one is referred to proximus. This single indi-
vidual was also obtained by Taylor on the same day and at the
same recorded altitude (4,632 feet) as an example of modicus.
The occurrence of two species of pocket gophers regarded as dis-
tinct in such close proximity is unusual. Zonal range : Upper Sono-
ran, as indicated by open stands of oaks (Quercus emoryi and
Quercus arizonica) ; altitude, 4,500 to 4,800 feet.

THOMOMYS UMBRINUS BURTI Huey

Santa Rita Mountain Pocket Gopher

Thomomys burti Huey, San Diego Soc. Nat. Hist. Trans. 7 (15): 15S, July
28, 1932.

Type. — From Madera Canyon, Santa Rita Mountains, Santa
Cruz County, Ariz, (altitude 6,000 feet) ; collected by W. H. Burt,
May 29, 1931.

General characters. — A small, dark subspecies, with a coloration
unusual except in closely allied forms ; upper parts between cinna-
mon and cinnamon-brown or russet, becoming uniformly blackish
along the moderately broad, well denned median area from top of
head to rump ; skull small, brain case smoothly rounded ; nasals
;wedge-shaped, emarginate posteriorly; auditory bullae small;
mammae, pectoral one pair, inguinal two pairs. Closely allied to
intermedins of the upper slopes of the Huachuca Mountains ; color
slightly paler, dentition heavier.

Measurements. — An adult male and an adult female topotype,
respectively : Total length, 217, 200 ; tail, 60, 61 ; hind foot, 27.5,
26 millimeters.

Distribution and habitat. — Restricted to the Santa Rita Moun-
tains, southern Arizona. Zonal range : from 4,500 feet altitude in

THE POCKET GOPHERS 35

the Upper Sonoran Zone near the mouth of Madera Canyon up to
8,000 feet in the Transition Zone near the summit. The burrows
are located in the softer soil, usually in small open meadows.

THOMOMYS UMBRINUS QUERCINUS Burt and Campbell

Pa.tarito Mountain Pocket Gopher

Thomomys burti quervinus Burt and Campbell, Jour. Mammal. 15 (2) : 150,
May 15, 1934.

Type. — From Peha Blanca Spring, Pajarito Mountains, Ariz.
(altitude 4,500 feet, near Mexican Boundary, north of Monu-
ment 128) ; collected by Berry Campbell, July 15, 1933.

General characters. — A small, cinnamon subspecies ; mammae,
pectoral one pair, inguinal two pairs. Closely allied to proximus,
but still smaller ; coloration of the same pattern and general tones ;
skull smaller, more delicate in structure; nasals slightly shorter,
reaching anterior plane of zygomata.

Measurements. — An adult male topotype : Total length, 198 ;
tail, 60 ; hind foot, 27 millimeters. Type, female, and an adult fe-
male topotype, respectively: 193, 182; 61, 56; 25, 25 millimeters.

Distribution and habitat. — The known range of this close rela-
tive of proximus is from 4,500 feet altitude at the type locality
in the Pajarito Mountains to about 6,000 feet in the pass over the
summit of the Patagonia Mountains. Both localities are in the
oak belt in the Upper Sonoran Zone. At Pena Blanca Spring
burrows indicating a small colony were found in gravelly soil
along a broad wash. At the time of the writer's visit in June the
ground was very dry, no fresh gopher excavations were in evi-
dence, and specimens were difficult to obtain. In the pass over the
Patagonia Mountains, where the slopes are steep and brush-cover-
ed, considerable search failed to reveal the excavations of any
gophers except those of the single individual taken.

THOMOMYS UMBRINUS INTERMEDIUS Mkakns

Huachuoa Mountain Pocket Gophkk

Thomomys fulvus intermedins Mearns, U. S. Nat. Mus. Proc. 10: 719, July
30, 1897.

Type. — From summit of the Huachuca Mountains, southern
Arizona (altitude 9,000 feet) ; collected by F. X. Holzner, Sep-
tember 6, 1893.

General characters. — A small, dark subspecies, closely allied
to burti of the Santa Rita Mountains ; color slightly darker ; skull
very similar, but nasals longer; dentition lighter.

Measurements. — Type: Total length, 200; tail, 66; hind foot,
26 millimeters.

36 NORTH AMERICAN FAUNA 59, FISH AND WILDLIFE SERVICE

Distribution and hubitat. — The type, from 9,000 feet altitude
near the summit of the Huachuca Mountains, is the only speci-
men examined and definitely assigned to this form. Specimens
from Fort Huachuca, near the north base of the mountains, are
referred to proximus.

THE POCKET GOPHERS

37

INDEX

[Principal pa#e references to a spec

absonus, Thomomys bottae, 3, 8, 10.
Thomomys perpallidus, 10.

albatus, Thomomys, 19.

Thomomys bottae, 2, 3, 16, 18, 19,
20, 21.
alexandrae, Thomomys, 3, 28.
alienus, Thomomys bottae, 3 19, 24,
apache, Thomomys bottae, 12.
aridieola, Thomomys bottae, 3, 21.
Arivaca pocket gopher, 33.
aureus, Thomomys, 11.

Thomomys bottae, 3, 11, 12, 14. 29.

baileyi, Thomomys, 1, 4,-5.

Big Sandy River pocket gopher, 14.

bottae, Thomomys, 1, 2, 6.

burti, Thomomys, 34.

Thomomys umbrinus, 5, 33, 34.

catalinae, Thomomys bottae, 3, 24, 25,
26, 27.

Thomomys fulvus, 25.
centralis, Thomomys bottae, 7, 30.
cervinus, Thomomys, 17.

Thomomys bottae, 3, 17, 21, 28,
Characters, 2.
Chiricahua Mountain pocket gopher,

27.
chiricahuae, Thomomys umbrinus, 27.
chrysonotus, Thomomys, 15.

Thomomys bottae, 3, 15, 31.
collinus, Thomomys bottae, 3, 2'], 24, 27.

Thomomys fulvus, 27.
Comobabi pocket gopher, 22.
comobabiensis, Thomomys bottae, 3. 22.
Coyote Mountain pocket gopher, 23.

depauperatus, Thomomys bottae, 3, 20.

Thomomys perpallidus. 20.
desertorum, Thomomys, 12.

Thomomys bottae, 3, 12, 14, 16, 29,
30.
desitus, Thomomys bottae, 3, 12, 14, 15,

17.
Detrital Valley pocket gopher, 12.

P^conomic status, 6.
extenuatus, Thomomys bottae, 3, 24,
25, 27, 31, 32.

Fawn-colored pocket gopher. 17.
flavidus, Thomomys fulvus. 15.
f 0880V, Thomomys. 33.

Thomomys talpoides, 5, 12. 33.
Fulvous pocket gopher, 13.
fulvus, Oeomys, 13.

Thomomys bottae, 3, 11, 13, 14. l.r>.
17. 23, 30.

Oeomys fulvus, 13.

Gila Bend pocket gopher. 21.

Golden pockel gopher, 15.

Graham Mountains pocket jropher. 23.

es in boldface: synonyms in italic]

grahamensis, Thomomys bottae, 3, 23,
24, 27.

Thomomys fulvus, 23.
Grand Canyon pocket gopher, 30.
Group, Thomomys baileyi, 1, 4, 5 (dis-
trib. map), 31.

Thomomys bottae, 1, 2, 3 (distrib.

map), 7.
Thomomys talpoides, 1, 5 (distrib

map), 32.
Thomomys umbrinus, 1, 5 (distrib
map),*6, 33.
Growler Valley pocket gopher, 22.
growlerensis, Thomomys bottae, 3, 22.

Harquahala Mountain pocket gopher,

16.
harquahalae, Thomomys, 3, 31.
Hassayampa Valley pocket gopher. 16
House Rock Valley pocket gopher, 10
Huachuca Mountain pocket gopher. 35
Hualpai Mountains pocket gopher. 14.
hualpaiensis, Thomomys bottae, 3, 14.
hueyi, Thomomys bottae, 3. 24. 26.

intermedins, Thomomys fulvus, 35.

Thomomys umbrinus. 5, 34, 35.
Interniountain pocket gopher, 26.

Kaibab Plateau pocket gopher, 32.
kaibabensis, Thomomys fossor, 32.
Thomomys talpoides, 5, 32.

latirostris, Thomomys, 11.

Mearns pocket gopher, 31.
mearnsi, Thomomys, '■'•1.

Thomomys baileyi, 5, 24, 25, 31.
modicus. Thomomys bottae, 3, 18, 22,

23, 2.1, 28, 33, 34.

Thomomys fulvus, 28.
Mount Trumbull pocket gopher, 9.
muralis, Thomomys, 3, 4. 30.
mutabilis, Thomomys bottae, 3, 14, 15,

17. 18, 19.

nasutus, Thomomys bottae. 13.
Navajo pocket gopher, 28.

nicholi. Thomomys bottae, :'>. 7. 9.

operosus, Thomomys bottae, 3, 15.

Painted Deserl pocket gopher, 11.
Pajarlto Mountain pockel gopher, 34.
parvulus, Thomomys bottae, 3. 26. 27.

patulus, Thomomys bottae. :'>. 15. 16.
Peeples Valley pocket gopher, 15.
peramplus, Thomomys bottae, 3, 11, 12.
33.

Thomomys fulvus, 12.
phasma, Thomomys bottae. '.). 20. 22.

Thomomys fulvus, 20.
Phoenix pocket gopher, 17.
Pinal Mountains pockel gopher, 18.

38 NORTH AMERICAN FAUNA 59, FISH AND WILDLIFE SERVICE

pinalensis, Thomomys bottae, 3, 18.
planirostris, Thomomys bottae, 3, 8, 9,
10.

Thomomys perpallidus, 8.
Pocket gopher, Arivaea, 33.

Big Sandy River, 14.

Chiricahua Mountain, 27,

Comobabi, 22.

Coyote Mountain, 23.

Detrital Valley, 12.

fawn -colored, 17.

fulvous, 13.

Gila Bend, 21.

golden, 15.

Graham Mountains, 23.

Grand Canyon, 30.

Growler Valley, 22.

Harquahala Mountain, 16.

Hassayampa Vallev, 16.

House Rock Valley, 10.

Huachuca Mountain, 35.

Hualpai Mountains, 14.

intermountain, 26.

Kaibab Plateau, 32.

Mearns, 31.

Mount Trumbull, 9.

Navajo, 28.

Painted Desert, 11.

Pajarito Mountain, 35.

Peeples Valley, 15.

Phoenix, 17.

Pinal Mountains, 18.

Ranegras Plain, 31.

Rincon Mountains, 26.

Rocky Mountain, 33.

Santa Catalina, 25.

Santa Rita Mountain, 34.

Searchlight Ferry, 29.

Shivwits Plateau, 7.

Sulphur Springs Valley, 24.

Tinajas Altas, 20.

Tule Desert, 20.

Tunitcha Mountain, 12.

Upper Gila Valley, 19.

Verde Valley, 17.

Virgin Valley. 7.

whitish, 19.

Zion Park, 8.
proximus, Thomomys burti, 33.

Thomomys umbrinus, 5, 33. .*!4, \\T,.
pusillus, Thomomys bottae, 3, 23.

Thomomys fulvus, 23.

guericmus, Thomomys burti, 35.
Thomomys umbrinus, 5, 35.

Ranegras Plain pocket gopher, 31.
Rincon Mountains pocket gopher, 26.
riparius, Thomomys bottae, 16.
Rocky Mountain pocket gopher, 32.

Santa Catalina pocket gopher, 25.
Santa Rita Mountain pocket gopher,

34.
Searchlight Ferry pocket gopher, 29.
Shivwits Plateau pocket gopher, 7.
suboles, Thomomys, 3, 29.

suboles, Thomomys — Continued.

Thomomys fulvus, 29.
subsimilis, Thomomys bottae, 3, 16.

Thomomys fulvus, 16.
Sulphur Springs Valley pockel gopher,

24.
talpoides, Thomomys, 1, 5, 6.
Thomomys albatus, 19.

alexandrae, 3, 28.

a ii reus, 11.

baileyi, 1, 4, 5.

baileyi mearnsi, 5, 24, 25, 31.

bottae, 1, 3 (distrib. map), C>.

bottae absonus, 3, 8 10.

bottae albatus, 2, 16, 18, 19, 20, 21.

bottae alienus, 3, 19, 24.

bottae apache, 12.

bottae aridicola, 3, 21.

bottae aureus, 3, 11, 12, 14, 29.

bottae catalinae, 3, 24, 25, 26, 27.

bottae centralis, 7, 30.

bottae cervinus, 3, 17, 21, 28.

bottae chrysonotus, 3, 15, 31.

bottae collinus, 3, 23, 24, 27.

bottae comobabiensis, 3, 22.

bottae depauperatus, 3, 20.

bottae desertorum, 3, 12, 14, 16. 29,
30.

bottae desitus, 3, 12, 14, 15, 17.

bottae extenuatus, 3, 24, 25, 27, 31,
32.

bottae fulvus, 3, 11, 13, 14, 15, 17,
23, 30.

bottae grahamensis, 3, 23, 24, 27.

bottae growlerensis, 3, 22.

bottae hualpaiensis, 3, 14.

bottae hueyi, 3, 24, 26.

bottae modicus, 3, 18, 22, 23, 25,
28, 33, 34.

bottae mutabilis, 3, 14, 15, 17, IS,
19.

bottae nasutus, 13.

bottae nicholi, 3, 7, 9.

bottae operosus, 3, 15.

bottae parvulus, 3, 26, 27.

bottae patulus, 3, 15, 16.

bottae peramplus, 3, 11, 12, 33.

bottae phasma, 3, 20, 22.

bottae pinalensis, 3, 18.

bottae planirostris, 3, 8, 9, 10.

bottae pusillus, 3, 23.

bottae riparius, 16.

bottae subsimilis, 3, 16.

bottae toltecus, 19.

bottae trumbullensis, 3, S, 9.

bottae virgineus, 3, 7, 8.

burti, 34.

burti proximus, 33.

burti guescinus, 35,

cervinus, 17.

ch/rysonotus, 15.

desertorum, 12.

fossor, 32.

fossor kaibabensis, 32.

fulvus cataMnae, 25.

fulvus oolUnus, 27.

fulvus flavidus, in.

THE POCKET GOPHERS

39

Thomomys — Continued.

fulvus grahamensis, 23.
fiilvus intermedins, 35.
fnlvus modi ens, 28.
fulvus mutabilis, 17.
fnlvus peramplus, 12.
fulvus phasma, 20.
fulvus pusillus, 23.
fulvus suboles. 29.
fulvus subsimilis, 16.
harquahalae, 3, 31.
latirostris, 11.
mearnsi, 31.
muralis, 3, 4, 30.
perpallidus absonus, 10.
perpallidus depauperatus, 20.
perpallidus planirostris, 8.
suboles, 3, 29.
talpoides, 1, 5, 6.
talpoides fossor, 5, 6, 12, 33.
talpoides kaibabensis, 5, 32.
umbrinus, 1, 5, 6.

umbrinus burti, 5, 33, 34.

umbrinus chiricahuae, 27.

umbrinus intermedins, 5, 34, 35.

umbrinus proximus. 5, 33, 34, 35.

umbrinus quereinus. 5, 35.
Tinajas Altas pocket gopher, 20.
toltecus, Thomomys bottae, 19.
Tule Desert pocket gopher, 20.
Tunitcha Mountain pocket gopher, 12.
trumbullensis, Thomomvs bottae, 3, 8,
9.

umbrinus, Thomomys, 1, 5, 6.

Upper Gila Valley pocket gopher, 19.

Verde Valley pocket gopher, 17.
Virgin Valley pocket gopher, 7.
virgineus, Thomomys bottae, 3, 7, 8.

Whitish pocket gopher, 19.

Zion Park pocket gopher, 8.

U. S. GOVERMENT PRINTING OFFICE: 1947-696493

OCCIDENTAL COLLEGE LIBRARY

1 49.30:59 docus

The pocket gophers (genus Tho/Goldman, E

3 5043 00317 4405

DATE DUE

Demco, Inc. 38-293