The plateau pocket gopher, _Cratogeomys castanops_, inhabits open
lands from southeastern Colorado southward onto the Mexican
Plateau as far south as southern San Luis Potosi and southeastern
Zacatecas and southeastward to the Coastal Plain of northern
Tamaulipas. This species occurs at elevations from as low as 26 feet
at Matamoras in Tamaulipas to as high as 8700 feet in valleys of
south-eastern Coahuila. In 1934, Nelson and Goldman (Proc. Biol. Soc.
Washington, 47:135-154, June 13, 1934) revised the genus _Cratogeomys_
and decided that six subspecies of _C. castanops_ occurred in
Coahuila. In the present account, we describe four previously unknown
subspecies from Coahuila, exclude from the state two others recorded
from there by Nelson and Goldman, and show that three others named
previously from adjacent Mexican states do occur in Coahuila. This
makes eleven subspecies now known from that state. From Coahuila
Nelson and Goldman had 35 study specimens of _C. castanops_ from seven
localities and we have had 234 specimens from 63 localities.
Consequently we have been able to define with greater certainty, than
formerly was possible, the geographic distribution of _C. castanops_
in this Mexican state and similarly analyze more completely the
geographic variation.
Coahuila is near the center of the geographic range of _C. castanops_.
The occurrence of 11 subspecies within the state seems to be
the result of partial or perhaps, in some cases, total isolation of
populations of _C. castanops_ because of the highly dissected
topography and the variability of the soil. _Cratogeomys castanops_ is
a sedentary animal preferring open plains mantled by suitable soils,
preferably sandy in texture, in which the animals can dig their
elaborate underground systems of runways. Thin soils of hard texture
and rocky soils do not offer optimum habitat for _C. castanops_, and
the animals usually are absent or uncommon in such situations. Desert
mountains with their thin rocky soils, elevated passes, perpendicular
rocky cliffs, and stands of oaks and conifers at higher elevations
present impassable barriers for pocket gophers of this species. The
Rio Grande, bordering Coahuila to the north, in many places flowing
through steep-walled canons, also seems to be a barrier that this
fossorial rodent does not cross; distinct subspecies occur on the two
sides of the river directly opposite each other (also see Nelson and
Goldman, _op. cit._: 143). Smaller streams, such as the Rio Salado,
Rio Nazas and Rio Salinas, seem to be unimportant barriers to the
passage of these pocket gophers. The food supply of _C. castanops_
seems adequate in most situations and consequently food is unimportant
in governing the distribution of this species. Principal foods of _C.
castanops_ are fleshy tuberous roots of well-distributed desert
shrubs, but in the valleys of the high mountains of southeastern
Coahuila, where desert shrubs are absent, roots and leaves of
low-growing forbs are eaten.
Three distinct habitats for _C. castanops_ occur in Coahuila. The
state is crossed by a series of mostly impassable, mountainous ridges
beginning at the northwestern boundary at the Canon de Boquillas on
the Rio Grande and extending southeastward to the east-central border.
This divides Coahuila into a more humid and less elevated northeastern
area which is an inland extension westward of the Coastal Plain and a
more arid and higher western and southern area which is a part of the
"Mesa del Norte" of the Mexican Plateau. In the extreme southeast the
still higher elevated plains and intermontane valleys within the
Sierra Madre Oriental afford a third habitat for populations of this
species. The subspecies of these pocket gophers found in any one of
these three habitats show greater affinity to each other than they do
to any subspecies found in the other habitats.
Generally speaking, populations of _C. castanops_ from northeastern
Coahuila are related, as a group, in color and cranial features.
Partial isolation of subspecies in this area results chiefly from
discontinuity of suitable soils rather than from topography. These
pocket gophers occur most commonly in the deep, sandy soils which are
found along streams, especially where farm lands are irrigated. In
western and southern Coahuila, mountains extending in both north-south
and east-west directions act as partial barriers to the passage of _C.
castanops_. Within this large area, pocket gophers occur in desert
basins many of which are enclosed on two or more sides by mountains.
Even so, with the exception of the smaller _C. c. consitus_ of
northwestern Coahuila, all known subspecies occurring at lower
elevations in the western and southern part of the state show close
relationships in color and cranial features. Those subspecies in the
higher parts of southeastern Coahuila by their small size and dark
color reflect to a high degree their isolation in an elevated habitat.
Males of _C. castanops_ differ greatly from females of equal age;
consequently animals of the same sex, as well as of the same age, are
used herein for taxonomic comparisons. Since, of any given age-group,
females show less individual variation than do males, we have relied
more on the characteristics of the females in this taxonomic study.
Only specimens taken at approximately the same times of the year have
been compared for color of pelage. Capitalized color terms are those
of Ridgway, Color Standards and Color Nomenclature, Washington, D. C.,
1912. Specimens made available through the courtesy of the authorities
of the Biological Surveys Collection of the United States National
Museum are indicated in the accounts of subspecies as BSC; other
specimens listed are in the collection of the University of Kansas
Museum of Natural History. Assistance with field work is acknowledged
from the Kansas University Endowment Association and the National
Science Foundation.
In any one of the lists of "Specimens examined" beyond, the order of
arrangement of the localities is from north to south. Those localities
listed in Roman type are represented on the distribution map (Figure
1) by blacked-in circles. Each of several circles covers two or more
localities because the localities are close together. In any such
instance the northernmost place is listed in Roman type and the names
of the other places follow in Italic type. Measurements in millimeters
are given in table 1 for females and in table 2 for males.
+Cratogeomys castanops convexus+ Nelson and Goldman
1934. _Cratogeomys castanops convexus_ Nelson and Goldman, Proc. Biol.
Soc. Washington, 47:142, June 13, type from 7 mi. E Las Vacas
[= Villa Acuna], Rio Grande Valley, Coahuila (opposite Del Rio,
Texas).
_Distribution._--Extreme northern Coahuila, east and north of the
Serranias del Burro (see fig. 1).
_Diagnosis._--Previously known from only one specimen, a subadult
female, this subspecies has not been well diagnosed. At hand we have
five near topotypes of _convexus_ (including two adult females and one
adult male) and specimens assignable to this subspecies from several
other localities. This subspecies may be characterized as follows:
Size medium (see tables 1 and 2); dorsal profile of skull convex in
females and flat, especially posteriorly, in males; zygomata weakly
constructed and not widely flaring; mastoid and tympanic bullae
inflated; nasals short; rostrum broad and short; maxillary teeth
large.
[Illustration: ~Fig. 1.~ Geographic ranges of the subspecies of
_Cratogeomys castanops_ found in Coahuila, Mexico.
Guide to subspecies 4. _C. c. bullatus_ 8. _C. c. subsimus_
1. _C. c. convexus_ 5. _C. c. ustulatus_ 9. _C. c. goldmani_
2. _C. c. consitus_ 6. _C. c. jucundus_ 10. _C. c. subnubilus_
3. _C. c. sordidulus_ 7. _C. c. excelsus_ 11. _C. c. planifrons_]
_Comparisons._--From topotypes of _Cratogeomys castanops angusticeps_
Nelson and Goldman, found to the north and east across the Rio Grande
in Texas, _convexus_ differs in: Body larger; upper parts more
reddish, especially on sides; skull with zygomata less heavy, nasals
broader, pterygoids smaller, maxillary teeth larger. For comparisons
of _convexus_ with the subspecies of _C. castanops_ found to the west,
south and southeast, see accounts of the subspecies to follow.
_Remarks._--The geographic range of _convexus_ is restricted, being
bounded on the west and southwest by mountains, especially the
Serranias del Burro, and on the north and east by the Rio Grande. The
range of the subspecies found to the southeast may not be continuous
with that of _convexus_. At least, in the area between Villa Acuna and
Piedras Negras, along the Rio Grande, no specimens were obtained and
no sign was observed. We suspect that in this area the species occurs
only locally if at all.
A specimen taken near the Rio Grande in Coahuila, opposite Samuels,
Texas, and assigned to _Cratogeomys castanops clarkii_ by Nelson and
Goldman (op. cit.:140), has been examined by us and is referable to
_convexus_. This specimen is typical of _convexus_ except for the
lesser inflation of the mastoid bullae and tympanic bullae.
Conspicuous differences between _convexus_ and _angusticeps_
indicate that the Rio Grande is an effective barrier to passage by
these rodents.
_Specimens examined._--Total, 14, all from Coahuila: Rio Grande, 17
mi. S Dryden, Terrell Co., Texas, 6; Rio Grande, opposite Samuels, Val
Verde Co., Texas, 1 (BSC); Villa Acuna, 5; Canon del Cochino, 21 mi. E
and 16 mi. N Piedra Blanca, 1; 11 mi. W Hda. San Miguel, 1.
+Cratogeomys castanops bullatus+ new subspecies
_Type._--Female, adult, skin and skull, No. 48498, Univ. Kansas Mus.
Nat. Hist., 2 mi. S and 6-1/2 mi. E Nava, 810 ft., Coahuila; 16 June
1952; obtained by Robert J. Russell, original number 276.
_Distribution._--Desert lowlands of northeastern Coahuila, from the
Rio Grande to as far southwestward as the Rio Sabinas (see fig. 1).
_Diagnosis._--Body medium for the species (see tables 1 and 2); tail
long; hind foot small; upper parts Light Ochraceous-Buff (in summer
pelage) and Orange-Buff (in winter pelage), bases of hairs Plumbeous;
underparts white to pale buffy; skull small, broad and slightly convex
in dorsal outline; zygomata widely flaring; palate short; rostrum
short; nasals short; mastoid and tympanic bullae inflated;
basioccipital with lateral edges parallel; maxillary teeth small.
_Comparisons._--From _Cratogeomys castanops convexus_, found to the
north, _bullatus_ differs in: Hind foot shorter; skull much broader in
relation to length; rostrum narrower but, relative to length of skull,
wider; tympanic bullae slightly more inflated; incisors and maxillary
teeth smaller. From topotypes of _Cratogeomys castanops angusticeps_,
found across the Rio Grande and upstream from localities where
_bullatus_ is known to occur, _bullatus_ differs in: Body slightly
smaller; color paler, especially on sides; skull shorter and broader;
rostrum shorter and broader; nasals shorter; mastoid and tympanic
bullae more inflated; maxillary teeth smaller. For comparisons of
_bullatus_ with the subspecies of _C. castanops_ found to the west and
south, see accounts of the subspecies to follow.
_Remarks._--_Cratogeomys castanops bullatus_ in small size resembles
_C. c. tamaulipensis_ Nelson and Goldman of the lower Rio Grande
Valley in Tamaulipas, but the two differ markedly in cranial features.
_Cratogeomys c. bullatus_ is smaller than _convexus_ but these two
subspecies resemble each other in color and cranial characters. Both
have an arched skull, inflated mastoid and tympanic bullae, short
nasals, and a short rostrum. Comparison of _bullatus_ with
_angusticeps_, which occurs across the Rio Grande but not directly
opposite the range of _bullatus_, indicates that these two subspecies
are less closely related than _bullatus_ is to _tamaulipensis_ and
_convexus_.
_Cratogeomys castanops bullatus_ is especially common in sandy
soils in the vicinity of Nava where the mounds were in fallow
irrigated fields and other open places between extensive live oak
thickets. South and west of the Rio Grande the animals were less
abundant and lived in heavier soils usually as individuals or in small
groups. Specimens were taken at elevations from as low as 800 feet to
as high as 2,000 feet.
_Specimens examined._--Total, 24, from: 2 mi. S and 6-1/2 mi. E Nava,
810 ft., 2; 2 mi. S and 12 mi. E Nava, 800 ft., 1; _3 mi. S and 12 mi.
E Nava, 800 ft._, 4; 29 mi. N and 6 mi. E Sabinas, 5; 10 mi. E
Hacienda La Mariposa, 2000 ft., 1; La Gacha [= La Concha], 1600 ft.,
8; 8 mi. S and 8 mi. E Hacienda La Mariposa, 1900 ft., 1; 9 mi. S and
11 mi. E Sabinas, 1050 ft., 2.
+Cratogeomys castanops ustulatus+ new subspecies
_Type._--Female, adult, skin and skull, No. 34589, Univ. Kansas Mus.
Nat. Hist., Don Martin, 800 ft., Coahuila; 19 August 1949; obtained by
W. Kim Clark, original number 1034.
_Distribution._--Extreme northeastern Coahuila from the vicinity of
Presa Don Martin southward into northwestern Neuvo Leon in the valley
of the Rio Salado and its tributaries at least as far south as the
vicinity of Vallecillo (see fig. 1).
_Diagnosis._--Body large for species (see tables 1 and 2); hind foot
short; upper parts Apricot Buff (in fresh summer pelage) and
Salmon-Buff strongly mixed with black (in fresh winter pelage);
underparts Light Ochraceous-Buff; skull large, especially in females,
and broad; zygomatic arches widely flaring; palate long; rostrum
broad; nasals long; mastoid and tympanic bullae not conspicuously
inflated; incisors narrow; maxillary teeth large.
_Comparisons._--From _Cratogeomys castanops bullatus_ found to the
north, _ustulatus_ differs in: Body larger; tail shorter; upper parts
darker, more rufous and less buffy; skull larger, especially in
palate, nasals, and rostrum; zygomata more widely flaring; tympanic
bullae less inflated; incisors slightly larger; maxillary teeth
larger. From topotypes of _Cratogeomys castanops tamaulipensis_
found to the southeast, _ustulatus_ differs in: Body larger; upper
parts, in winter pelage, darker, more rufous and less buffy;
underparts paler; skull larger, especially in palate, rostrum and
nasals; zygomata more widely flaring; tympanic bullae more inflated;
pterygoids larger; basioccipital narrower, its sides parallel instead
of convex; maxillary teeth smaller. From _Cratogeomys castanops
subsimus_, found to the southwest, _ustulatus_ differs in: Tail
shorter; hind foot smaller; upper parts darker, more rufous and less
pinkish-buff; skull shorter; zygomata less widely flaring; palate
shorter; rostrum averaging slightly narrower; nasals shorter; incisors
narrower; maxillary teeth slightly smaller. For comparison of
_ustulatus_ with the subspecies of _C. castanops_ to the southwest,
see account of that subspecies to follow.
_Remarks._--_Cratogeomys castanops ustulatus_ is a large-sized pocket
gopher with a relatively larger, skull. In size oL skull, _ustulatus_
is exceeded only by _C. c. subsimus_ found beyond the mountains in the
southern part of Coahuila. In size, _ustulatus_ differs so markedly
from _bullatus_ that the two can be distinguished easily by this
feature alone. The skull of _C. c. convexus_ approaches that of
_ustulatus_ in size, but is smaller in all respects, save breadth of
rostrum.
This pocket gopher is found commonly along the Rio Salado and its
watershed. Fallow cotton fields in the vicinity of Anahuac [=
Rodriques], Nuevo Leon, are preferred living places. This subspecies
was found at elevations as high as 1000 feet and as low as 600 feet.
_Specimens examined._--Total, 10, from: Don Martin, 800 ft., 5; _base
of Don Martin Dam_, 2; _2 mi. SE Don Martin Dam, along Rio Salado_, 2;
5 mi. SE Don Martin, 1.
_Records from Nuevo Leon._--Total, 14, from: 9 mi. N and 2 mi. W
Anahuac [= Rodriques], 1; 4 mi. N and 1 mi. W Anahuac [= Rodriques],
5; 3 mi. N Lampazos, 4; 1 mi. N Vallecillo, 1000 ft., 1; Vallecillo,
20 mi. S Rio Salado, 1000 ft., 3.
+Cratogeomys castanops jucundus+ new subspecies
_Type._--Female, adult, skin and skull; No. 56603, Univ. Kansas Mus.
Nat. Hist.; Hermanas, 1205 ft., Coahuila; 5 December 1953; obtained by
Robert W. Dickerman, original number 2051.
_Distribution._--Arid plains and broad intermontane valleys of
east-central Coahuila (see fig. 1).
_Diagnosis._--Body largest for the species (see table 1); tail long;
hind foot large; upper parts in winter pelage Ochraceous-Buff, in
summer pelage Antimony Yellow; underparts Pale Ochraceous-Buff; skull
medium in size, broad; zygomata moderately flaring; palate medium in
length; rostrum broad; nasals moderately long; maxillary teeth small.
_Comparisons._--From _Cratogeomy castanops ustulatus_, found to the
east, jucundus differs in: Body larger; tail longer; hind foot larger;
upper parts paler, more ochraceous and less rufous; skull averaging
smaller; zygomata slightly less expanded laterally; palate and nasals
shorter; squamosal breadth less; mastoid bullae less inflated,
especially in females; rostrum slightly narrower; maxillary tooth-row
shorter. From topotypes of _Cratogeomys castanops tamaulipensis_,
found to the southeast, _jucundus_ differs in: Body larger; tail
longer; hind foot smaller; upper parts, in winter pelage, paler, more
ochraceous and less rufous; skull larger; zygomata more widely
flaring; palate longer; rostrum broader; tympanic bullae more
inflated; basioccipital with sides parallel instead of convex;
maxillary teeth smaller. From _Cratogeomy castanops excelsus_, found
to the southwest, _jucundus_ differs in: Body larger; hind foot
averaging larger; upper parts darker, more ochraceous, and less buffy;
underparts darker, more buffy and less whitish; skull slightly
smaller; zygomata less widely flaring, especially in females; palate
shorter; nasals shorter; squamosal breadth less; mastoid bullae more
inflated; incisors narrower. From _Cratogeomys castanops subsimus_,
found to the south, _jucundus_ differs in: Body larger; tail shorter;
hind foot shorter; upper parts paler, more ochraceous and less
yellowish; skull smaller; zygomata less widely expanded laterally;
palate and nasals shorter; rostrum narrower; squamosal breadth less;
maxillary tooth-row shorter. From _Cratogeomys castanops bullatus_,
found to the north, _jucundus_ differs in: Body larger; tail averaging
longer; hind foot larger; color of upper parts more ochraceous and
less rufous; underparts darker, more buffy and less whitish; skull
larger, especially in length, in width across zygomata, in lengths of
palate, rostrum and nasals; mastoid and tympanic bullae less inflated;
squamosal breadth greater.
_Remarks._--_Cratogeomys castanops jucundus_ is large, exceeding
subsimus in dimensions of the body, but differing from _subsimus_ in
relatively smaller skull. Passage to the north and northeast by
_jucundus_ is at least partly blocked by inhospitable mountainous
country; the resulting semi-isolation may be one reason for the
distinctive characteristics of _jucundus_ compared with those of
_bullatus_ and _ustulatus_. Two specimens from Monclova, assigned to
_tamaulipensis_ by Nelson and Goldman (op. cit.:142), are here
referred to _jucundus_ on the basis of cranial characters and size.
Specimens were trapped in fallow irrigated fields in the vicinity
of Monclova. Others were taken in deep soils in desert flats.
_Specimens examined._--Total, 19, from: Hermanas, 1205 ft., 9; _1 mi.
S Hermanas_, 2; 1 mi. N and 13 mi. E Cuatro Cienegas, 2; 5 mi. N and
2 mi. W Monclova, 1; _2 mi. N and 1 mi. E Monclova_, 1; Monclova, 2
(BSC); Hisachalo [= Huisachalo], 2.
+Cratogeomys castanops sordidulus+ new subspecies
_Type._--Female, adult, skin and skull; No. 56614, Univ. Kansas Mus.
Nat. Hist.; 1.5 mi. NW Ocampo, 3300 ft., Coahuila; 16 December 1953;
obtained by Robert W. Dickerman, original number 2164.
_Distribution._--Desert plains of north-central Coahuila, surrounded
for the most part by higher mountainous country (see fig. 1).
_Diagnosis._--Body large for species (see tables 1 and 2); tail short;
hind foot large; upper parts Ochraceous-Buff (in summer pelage) and
Orange-Buff (in fresh winter pelage); underparts Pale
Ochraceous-Salmon; skull medium in size and narrow; zygomata narrow;
rostrum narrow; palate short; nasals medium in length; basioccipital
small and narrow; mastoid bullae not greatly inflated; tympanic bullae
inflated; incisors small; maxillary teeth small.
_Comparisons._--From _Cratogeomys castanops jucundus_, found beyond
the mountains to the southeast, _sordidulus_ differs in: Body smaller;
tail shorter; hind foot slightly smaller; upper parts darker, more
ochraceous and less yellowish, with plumbeous bases of hairs more
conspicuous; underparts darker, more buffy and less whitish; skull
slightly shorter, more nearly flat, and narrower; zygomata less widely
flaring; rostrum narrower; mastoid bullae less inflated; incisors and
maxillary teeth slightly smaller. From _Cratogeomys castanops
excelsus_, found to the south and southwest, _sordidulus_ differs in:
Body slightly smaller; tail shorter; hind foot slightly larger; upper
parts darker, more ochraceous and less pinkish-buff; underparts
darker, more buffy and less whitish; skull smaller and narrower;
zygomata less widely flaring; sides more nearly parallel and not
expanded anteriorly; palate shorter; rostrum narrower and, in relation
to greatest length of skull, longer; tympanic bullae slightly more
inflated; incisors and maxillary teeth smaller. From _Cratogeomys
castanops consitus_, found to the north and west, _sordidulus_ differs
in: Body larger; hind foot larger; upper parts paler, more ochraceous
and less rufous; skull decidedly larger and wider; zygomata more
widely flaring; palate and nasals longer; rostrum broader; mastoid
bullae and tympanic bullae larger; maxillary teeth smaller. From
topotypes of _Cratogeomys castanops clarkii_ (Baird), found to the
northwest, _sordidulus_ differs in: Body larger; tail shorter; upper
parts, in winter pelage, paler, more ochraceous and less dark-rufous;
skull slightly smaller and narrower; rostrum narrower; nasals slightly
shorter; sides of basioccipital more nearly parallel instead of
wedge-shaped; mastoid bullae less inflated; incisor and maxillary
teeth smaller. From _Cratogeomys castanops convexus_, found to the
northeast, _sordidulus_ differs in: Body larger; tail shorter; upper
parts slightly darker, more ochraceous and less buffy; skull narrower;
zygomata more nearly parallel and less expanded anteriorly; rostrum
narrower and longer; nasals longer; squamosal breadth greater; mastoid
bullae less inflated; maxillary teeth smaller. From _Cratogeomys
castanops bullatus_, found to the east, _sordidulus_ differs in: Body
larger; hind foot larger; upper parts darker, more ochraceous and less
buffy; skull larger in all respects; zygomata more widely flaring;
tympanic bullae less inflated; maxillary teeth larger.
_Remarks._--_Cratogeomys castanops sordidulus_ is limited to the
Llano de Ocampo, an elevated, desert plain surrounded on three sides,
west, south and east, by higher mountainous country which seems to bar
the passage of this rodent. On the eastern side this barrier extends
north to the very banks of the Rio Grande in the Canon de Boquillas.
This subspecies, therefore, is in contact with other populations of
_Cratogeomys_ only to the north and northwest. This subspecies is well
characterized by size, color and cranial characteristics.
_Cratogeomys castanops sordidulus_ is not abundant; groups of mounds
constructed by one or a few individuals were found in widely separated
places. Mounds were often small, appeared old and, in other ways, were
inconspicuous on arid flats. The animals were taken at elevations as
low as 3250 feet and as high as 4150 feet.
_Specimens examined._--Total, 13, from: 50 mi. N and 20 mi. W Ocampo,
4150 ft., 1; 18 mi. S and 14 mi. E Tanque Alvarez, 4000 ft., 4; 1-1/2
mi. NW Ocampo, 3300 ft., 6; _Ocampo_, 1; 5 mi. N and 19 mi. W Cuatro
Cienegas, 3250 ft., 1.
+Cratogeomys castanops consitus+ Nelson and Goldman
1934. _Cratogeomys castanops consitus_ Nelson and Goldman, Proc. Biol.
Soc. Washington, 47:140, June 13, type from Gallego, 5500 ft.,
Chihuahua.
_Distribution._--Arid high plains from central Chihuahua, east and
southeast at least into northwestern Coahuila (see fig. 1).
_Comparisons._--From _Cratogeomys castanops lacrimalis_ Nelson and
Goldman, specimens from Boquillas and Marathon north of the Rio Grande
in Texas, _consitus_ differs in: Body smaller; tail and hind foot
shorter; upper parts paler, more light buffy and less rufous;
underparts paler, light buffy instead of dark buffy; skull decidedly
smaller; zygomata slightly less widely flaring; palate especially
shorter; rostrum narrower; squamosal breadth less; incisors smaller.
From topotypes of _Cratogeomys castanops clarkii_, found to the north
along the Rio Grande, _consitus_ differs in: Body smaller; tail and
hind foot shorter; upper parts paler, more buffy and less rufous;
skull markedly smaller, especially in palate and nasals; zygomata less
widely flaring; tympanic bullae more inflated; mastoid bullae less
inflated; basioccipital parallel-sided as opposed to wedge-shaped.
From _Cratogeomys castanops convexus_, found to the east, _consitus_
differs in: Body smaller; tail and hind foot shorter; upper parts
paler, more buffy and less ochraceous; underparts paler, white or
light buffy instead of pale ochraceous; skull smaller; zygomata less
widely flaring; palate shorter; rostrum decidedly narrower and,
relative to length of skull, longer; squamosal breadth less; incisors
smaller. From _Cratogeomys castanops excelsus_, found to the south,
_consitus_ differs in: Size smaller; tail and hind foot shorter; upper
parts darker, more rufous and less pinkish-buff; skull conspicuously
smaller, especially in palate, rostrum, and nasals; zygomata less
widely flaring; mastoid bullae and tympanic bullae more inflated;
incisors smaller; maxillary teeth relatively larger. For comparison of
_consitus_ with _Cratogeomys castanops sordidulus_, see previous
account.
_Remarks._--_Cratogeomys castanops consitus_ is a small pocket gopher
(see tables 1 and 2); the largest adult available to us is much
smaller than the smallest adult of any adjacent subspecies. Specimens
from Coahuila assigned to _consitus_ compare favorably with
topotypes although those from the vicinity of Jaco are smaller, paler
and have a narrower rostrum and smaller maxillary teeth. An immature
male trapped three miles northeast of Sierra Mojada is tentatively
assigned to _consitus_. This subspecies seems to be rare in
northwestern Coahuila and small colonies are widely scattered.
_Cratogeomys castanops clarkii_ (Baird) may occur along the Rio
Grande in extreme northwestern Coahuila. No specimens are known from
Coahuila, and none was found in the vicinity of Boquillas, Coahuila,
in 1952.
_Specimens examined._--Total, 8, from: 3 mi. N and 9 mi. E El Pino, 1;
6 mi. E Jaco, Chihuahua, _in_ Coahuila, 6; 3 mi. NE Sierra Mojada, 1.
+Cratogeomys castanops excelsus+ Nelson and Goldman
1934. _Cratogeomys castanops excelsus_ Nelson and Goldman, Proc. Biol.
Soc. Washington, 47:143, June 13, type from San Pedro, 10 mi. W Laguna
de Mayran, Coahuila.
_Distribution._--Desert plains of southwestern Coahuila and
northeastern Durango (see fig. 1).
_Comparisons._--_Cratogeomys castanops excelsus_ is characterized by
large size and pale color; it is the palest subspecies of _C.
castanops_. Of adjacent subspecies, excelsus most closely resembles
_C. c. subsimus_ which occurs to the east and resembles least _C. c.
consitus_, which occurs to the northwest.
From _Cratogeomys castanops subsimus_, found to the east, _excelsus_
differs in: Body averaging slightly larger; tail and hind foot
shorter; upper parts paler, more light buffy and less yellowish; skull
smaller; palate especially shorter; rostrum narrower; nasals shorter;
incisors slightly smaller; maxillary tooth-row shorter. Compared with
topotypes of _C. c. goldmani_, found to the south, _excelsus_ differs
in: Body larger; hind foot smaller; upper parts in winter pelage
paler, more buffy and less rufous; skull larger; zygomata more widely
flaring; rostrum broader; nasals shorter; tympanic bullae larger and
more inflated; maxillary teeth larger.
Specimens of _excelsus_ from the vicinity of Torreon, in southwestern
Coahuila, are slightly smaller in cranial dimensions than more typical
examples of the subspecies. In small size, at least, these specimens
show some resemblance to _goldmani_ to the south. The range of
_excelsus_ approaches that of _C. c. consitus_ in west-central
Coahuila (see fig. 1), but no evidence of intergradation between these
two subspecies could be ascertained. For comparison of _excelsus_ with
_consitus_, see account of the latter.
_Remarks._--_Cratogeomys castanops excelsus_ lives in the deep soils
of the arid interior basin of southwestern Coahuila and adjacent
parts of Durango. This animal is common in the cultivated areas in,
and in the vicinity of, the formerly extensive Laguna de Mayran. East
of this laguna the land becomes progressively higher, and _C. c.
subsimus_ occurs in the higher, more dissected part of this area.
_Specimens examined._--Total, 33, from: 8 mi. E and 2 mi. S
Americanos, 3500 ft., 3; 4 mi. N Acatita, 3600 ft., 9; 20 mi. S El
Hundido, 1; San Pedro, 2 (BSC); _1 mi. SW San Pedro de las Colonias,
3700 ft._, 4; 10 mi. N and 11 mi. W San Lorenzo, 2; 2 mi. E Torreon,
12.
+Cratogeomys castanops subsimus+ Nelson and Goldman
1934. _Cratogeomys castanops subsimus_ Nelson and Goldman, Proc. Biol.
Soc. Washington, 47:144, June 13, type from Jaral, Coahuila.
_Distribution._--Desert plains and lower foothills of mountains in
south-central Coahuila (see fig. 1).
_Comparisons._--From _Cratogeomys castanops goldmani_, found to the
southwest, _subsimus_ differs in: Body larger; hind foot larger; upper
parts paler, more yellowish and less rufous; skull larger and rougher,
having more prominent ridges and crests and deeper fossae for
attachment of muscles; zygomata more widely flaring; palate longer;
rostrum broader; nasals longer; squamosal breadth greater; maxillary
teeth larger. From _C. c. subnubilus_, found to the south, _subsimus_
differs in: Body larger; tail and hind foot shorter; upper parts
paler, more yellowish-buff and less blackish; skull decidedly larger
in all respects. From _C. c. planifrons_, found at higher elevations
to the southeast, _subsimus_ differs in the same respects as
_subsimus_ differs from _subnubilus_. For comparisons between
_subsimus_ and subspecies to the west, north and northeast, see
accounts above.
TABLE 1. ~Measurements of Adult Female Cratogeomys
from Coahuila, Mexico~
Table legend:
Column A: No. av. or cat. no.
Column B: Total length
Column C: Length of tail
Column D: Length of hind foot
Column E: Condylobasal breadth
Column F: Zygomatic breadth
Column G: Length of palate
Column H: Breadth of rostrum
Column I: Length of nasals
Column J: Squamosal breadth
Column K: Alveolar length of maxillary tooth-row
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A B C D E F G H I J K
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_C. c. convexus_, Villa Acuna
52259 260 86 37 50.6 31.7 33.8 11.7 16.7 29.1 9.3
52261 265 83 38 49.3 31.6 32.9 11.8 15.8 28.9 10.6
_C. c. bullatus_, vicinity of Nava
5 Av. 256 80 36 47.4 30.6 32.6 10.7 17.1 27.9 9.5
Min. 242 72 35 47.0 30.6 32.3 10.0 16.5 27.5 9.2
Max. 263 85 37 47.7 31.1 32.9 11.6 17.8 28.2 9.8
_C. c. ustulatus_, vicinity of Don Martin
8 Av. 273 74 36 51.4 33.5 35.4 11.8 18.8 30.1 10.0
Min. 261 64 35 50.7 32.6 34.8 11.0 17.8 29.1 9.3
Max. 280 83 38 52.1 34.1 36.5 12.5 19.2 30.8 10.6
_C. c. jucundus_, Hermanas
4 Av. 296 85 39 50.9 33.0 34.6 11.5 18.0 29.6 9.4
Min. 294 83 38 49.8 32.1 33.8 11.0 17.0 29.0 9.1
Max. 298 86 39 51.8 33.8 35.0 11.6 18.6 30.1 9.6
_C. c. sordidulus_, 1.5 mi. NW Ocampo
3 Av. 276 79 37 50.4 31.7 34.6 10.9 18.2 30.0 9.1
Min. 270 75 36 49.5 30.6 33.8 10.3 17.7 29.8 8.9
Max. 288 85 39 51.4 32.4 35.2 11.4 18.5 30.1 9.2
_C. c. consitus_, 6 mi. E Jaco, Chihuahua, in Coahuila
4 Av. 229 74 32 43.8 28.1 29.6 9.7 16.0 26.2 8.9
Min. 226 68 31 42.6 27.3 29.4 9.4 15.5 25.7 8.1
Max. 232 78 32 45.8 28.8 29.9 9.9 16.2 26.9 9.2
_C. c. excelsus_, 4 mi. N Acatita
4 Av. 284 82 37 51.4 34.1 35.4 11.6 18.9 31.2 9.5
Min. 274 77 35 51.1 33.6 34.7 10.4 18.4 30.5 9.2
Max. 291 86 38 51.6 34.9 36.1 12.1 20.1 31.7 9.9
_C. c. subsimus_, 12 mi. N and 10 mi. E Parras
34937 287 87 39 53.1 34.9 36.9 11.5 19.4 31.7 10.5
Jaral (BSC)
51049 295 104 40 53.2 34.1 36.9 12.6 18.7 29.7 10.0
_C. c. goldmani_, 1 mi. S Jimulco
55611 250 85 35 46.0 32.6 31.4 10.7 16.3 27.8 9.8
_C. c. subnubilus_, 1 mi. S Carneros
33128 220 65 29 40.8 27.9 27.2 8.7 12.7 24.7 8.1
2 mi. W San Miguel
33132 222 65 30 40.4 26.3 26.6 8.1 13.2 24.5 8.4
1 mi. N Agua Nueva
33127 220 74 29 41.8 24.6 28.4 8.3 14.2 23.9 8.4
8 mi. N La Ventura
34934 235 76 30 42.2 27.9 28.5 9.0 14.3 26.3 7.8
_C. c. planifrons_, 12 mi. W San Antonio de las Alazanas
5 Av. 244 66 32 43.7 28.0 29.1 9.4 14.5 26.2 8.6
Min. 239 62 31 43.3 27.5 28.7 8.9 13.6 25.3 8.3
Max. 247 69 33 44.3 28.5 9.4 9.7 15.3 26.8 8.9
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