Part 2

A specimen taken near the Río 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 Río Grande is an effective barrier to passage by these rodents.

Specimens examined.--Total, 14, all from Coahuila: Río Grande, 17 mi. S Dryden, Terrell Co., Texas, 6; Río Grande, opposite Samuels, Val Verde Co., Texas, 1 (BSC); Villa Acuña, 5; Cañon 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 Río Grande to as far southwestward as the Río 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 Río 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 Río 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 Río 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 Río 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 León in the valley of the Río 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 o£ 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 Río Salado and its watershed. Fallow cotton fields in the vicinity of Anahuac [= Rodríques], Nuevo León, 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 Río Salado, 2; 5 mi. SE Don Martin, 1.

Records from Nuevo León.--Total, 14, from: 9 mi. N and 2 mi. W Anahuac [= Rodríques], 1; 4 mi. N and 1 mi. W Anahuac [= Rodríques], 5; 3 mi. N Lampazos, 4; 1 mi. N Vallecillo, 1000 ft., 1; Vallecillo, 20 mi. S Río 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 Ciénegas, 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