This newly described subspecies is known only from Cerro Viejo and is probably restricted to the higher elevations on this mountain.
Specimens examined.—Seven, Top of Cerro Viejo de Cuyutlán, 19 mi. S and 9 mi. W Guadalajara.
Cratogeomys zinseri zodius new subspecies
Type.—Male, adult, skull and skin, No. 31879 Mus. Nat. Hist., Univ. Kansas; from 13 mi. S and 15 mi. W Guadalajara, Jalisco, México; obtained on February 6, 1949, by J. R. Alcorn, original No. 7747.
Range.—Known only from the type locality.
Diagnosis.—Size small (see measurements); tail short; hind foot small; upper parts Sayal Brown, underparts Pinkish Buff, hind foot whitish; skull small, narrow; outline of dorsal profile of skull concave; zygomatic breadth narrow; nasals actually short, but relatively long; width across mastoid processes of squamosal short; auditory bullae inflated; interorbital constriction narrow; maxillary teeth relatively large.
Comparisons.—From topotypes of C. z. zinseri from Lagos, Jalisco, C. z. zodius differs in: Body smaller (see measurements); tail shorter, hind foot smaller; upper parts dull brownish instead of reddish-brown, underparts paler, hairs of feet whitish instead of brownish; skull smaller, especially in females, narrower; dorsal profile of skull concave or flat (females) rather than convex; zygomatic breadth less; rostrum narrower and shallower; nasals actually shorter, but relatively longer in relation to length of skull; width across mastoid processes of squamosal shorter; maxillary teeth smaller.
Measurements.—The type and an adult male (his measurements in parentheses) yield measurements as follows: Total length, 318 (324); length of tail, 95 (89); length of hind foot, 41 (41); occipitonasal length of skull, 60.5 (59.1); basilar length, 52.4 (51.8); zygomatic breadth, 40.6 (39.0); interorbital breadth, 8.3 (8.8); greatest height of cranium, as explained above, 22.6 (22.4); least depth of rostrum, 11.2 (10.4); breadth of rostrum, 13.3 (13.9); length of nasals, 21.7 (21.2); width across mastoid processes of squamosal, 37.1 (36.8); height of occiput, 17.7 (17.9); length of maxillary tooth-row, 13.0 (13.3). A nearly adult female measured: Total length, 292; length of tail, 81; length of hind foot, 39; occipitonasal length of skull, 53.3; basilar length, 46.5; zygomatic breadth, 34.1; interorbital breadth, 7.8; greatest height of cranium, 21.0; least depth of rostrum, 9.8; length of nasals, 18.0; width across mastoid processes of squamosal, 32.2; depth of occiput, 15.9; length of maxillary tooth-row, 12.1.
Remarks.—This newly described subspecies is the smallest of known races of C. zinseri, and it is seemingly more closely related to C. z. zinseri than to the subspecies newly named below from the north end of Lago Sayula. The skulls of females are especially small and delicate in structure; the males are larger with more massive skulls. C. z. zodius is known to occur in the foot hills north of the Cerro Viejo, the mountain from which C. g. atratus was described above.