low.

Sturnira ludovici occidentalis, new subspecies

_Holotype._--Adult female, skin and skull, no. 92798 Museum of Natural
History, The University of Kansas, from Plumosas, 2500 feet elevation,
Sinaloa; obtained on August 31, 1962, by Percy L. Clifton (original no.
2939).

_Distribution._--Western Mexico; known certainly from south-western
Durango south to southern Jalisco (see Fig. 1).

_Diagnosis._--Size small both externally and cranially (forearm in
adults 40.4-44.1 mm., greatest length of skull 21.7-22.9); rostrum
short and abruptly elevated; skull relatively broad; dorsal pelage drab
brownish over-all, usually lacking epaulets (pale yellowish brown when
present); ventral pelage brownish gray.

_Comparisons._--From _Sturnira ludovici ludovici_, the only other
subspecies of the species, _S. l. occidentalis_ differs in averaging
smaller in most external and cranial dimensions (in some measurements
the upper size limits of _occidentalis_ barely overlap the lower limits
in specimens of _ludovici_ examined), in having a relatively broader
skull with a shorter, more abruptly elevated rostrum, and in being
paler both dorsally and ventrally.

From _Sturnira lilium parvidens_, with which it is sympatric, _S. l.
occidentalis_ usually (but not always) differs in being brownish
(rather than yellowish to yellowish orange) dorsally and in lacking
epaulets, and differs in the following cranial features: first upper
incisors simple (rather than weakly bifid in unworn condition), larger,
and more nearly straight when viewed from the front; second upper
incisors reduced; lower incisors bilobate rather than trilobate;
lingual cusps on m1 and m2 greatly reduced; M2 usually turned inward
from M1 at distinct angle. The two species have approximately the same
external and cranial dimensions in western Mexico.

_Measurements_ (in millimeters).--External measurements of the holotype
are as follows: total length, 58; length of hind foot, 15; length of
ear, 18; forearm (average of both), 42.5. Corresponding average and
extreme measurements of 11 adults from 4 km. N Durazno, Jalisco,
followed by those of eight adults from 17 km. SE Talpa, Jalisco, are:
61.9 (59-65), 60.9 (57-68); 14.1 (12-15), 13.0 (13); 16.1 (15-18), 16.0
(15-17); 42.2 (40.4-43.8), 42.9 (41.6-44.1); weight in grams, 16.8
(15-19, six specimens only), 19.2 (16.3-22.5).

Cranial measurements of the holotype additional to those given in Table
1 are: condyloincisive