Specimens examined.—Seven, 13 mi. S and 15 mi. W Guadalajara.
Cratogeomys zinseri morulus new subspecies
Type.—Male, adult, skull and skin, No. 36679 Mus. Nat. Hist., Univ. Kansas; from N end Lago Sayula, 4400 ft., 9 mi. N and 2 mi. E Atoyac, Jalisco, México; obtained on March 23, 1950, by J. R. Alcorn, original No. 10889.
Range.—Known only from the type locality in central Jalisco.
Diagnosis.—Size large (see measurements); tail short; hind foot large; upper parts Fuscous-Black, strongly mixed with Walnut Brown, underparts Cinnamon-Buff, bases of all hairs Plumbeous; skull large, broad, rugose; outline of dorsal profile slightly concave, almost flat; zygomata strongly constructed, maxillary arm almost touching squamosal arm over jugal; wide across zygomata; nasals actually and relatively long; rostrum relatively narrow; auditory bullae inflated, relatively large; maxillary teeth relatively large.
Comparisons.—From topotypes of C. z. zinseri from Lagos, Jalisco, C. z. morulus differs in: Tail shorter (averaging 96 in females compared with 101, 94 in males compared with 115); color darker above, Fuscous-Black instead of Cinnamon-Rufous, underparts paler; skull larger (occipitonasal length 63.7 rather than averaging 58.5 in females and 68.6 rather than 63.1 in males); wide across zygomata; nasals actually and relatively longer; rostrum relatively narrower; wider across mastoid processes of squamosal; auditory bullae inflated, relatively larger; maxillary teeth larger.
From C. z. zodius, that occurs to the northeast, C. z. morulus differs in: Body larger (see measurements); hind foot larger; color of upper parts darker, underparts paler; skull much larger, broader, more rugose; dorsal profile of skull slightly concave rather than convex; wider across zygomata; nasals actually and relatively longer; rostrum broader, more massive; wider across mastoid processes of squamosal; auditory bullae larger; maxillary teeth larger.
Measurements.—The type and an adult female (her measurements in parentheses) from the type locality measure: Total length, 358 (338); length of tail, 94 (97); length of hind foot, 49 (45); occipitonasal length of skull, 68.6 (63.7); basilar length, 58.0 (55.6); zygomatic breadth, 49.3 (45.0); interorbital breadth, 9.6 (8.9); greatest height of cranium, as explained above, 26.1 (24.6); least depth of rostrum, 12.5 (10.8); breadth of rostrum, 14.5 (13.7); length of nasals, 25.9 (22.5); width across mastoid processes of squamosal, 47.7 (42.8); height of occiput, 19.8 (17.8); length of maxillary tooth-row, 13.9 (13.8).
Remarks.—Cratogeomys zinseri morulus is the darkest subspecies known of C. zinseri. It differs widely from other subspecies of this species in color and the large size of the skull.
Cratogeomys zinseri occurs over the same general area as C. gymnurus in central Jalisco, although these two species seemingly do not share the same local habitat. C. zinseri differs from C. gymnurus as follows: Tail relatively longer; skull wider across zygomatic arches than across mastoid processes of squamosal (reverse true in C. gymnurus); zygomata strongly bowed outward anteriorly; maxillary arm of zygomata almost touching squamosal arm (instead of widely separated from each other) above jugal; rostrum relatively narrower, less massive; border of nasals parallel or laterally swollen instead of gradually tapering.