length, 19.7; breadth across upper canines, 5.5;
length of mandibular tooth-row (c-m3), 6.7.

_Remarks._--The pattern of geographic variation in size in _Sturnira
ludovici_ resembles that in many other species of tropical bats in
North America in that individuals from the northern parts of the range
are smaller than those from the south. Mexican specimens herein
assigned to _S. l. ludovici_ average somewhat smaller than specimens
from Central America and the northern part of South America (but are
within the currently understood size limits of that subspecies) and
average paler as well. Additional material is needed from central and
eastern Mexico before the limits of distribution of the two subspecies
of _ludovici_ can be determined accurately.

All specimens examined of the new subspecies were trapped in mist nets.
The holotype was captured in a net stretched across an old road among
large fruit trees situated along a small river (a tributary of the Rio
del Baluarte). Tropical deciduous vegetation grew in the narrow valley
of the river but the adjacent hills supported oak. A specimen of
_Artibeus jamaicensis jamaicensis_ was netted along with the holotype
and on the previous night, August 30, one individual each of
_Glossophaga soricina leachii_ and _Sturnira lilium parvidens_ were
taken in the same net. Baker and Greer (1962:69) also reported the two
species of _Sturnira_ as netted together 6 mi. S Pueblo Nuevo in
adjacent Durango.

TABLE 1.--SOME MEASUREMENTS OF ADULTS OF TWO SUBSPECIES OF STURNIRA
LUDOVICI.

Table Legend:

Col. A: Number of specimens averaged, or catalogue number, and sex
Col. B: Length of forearm
Col. C: Greatest length of skull
Col. D: Zygomatic breadth
Col. E: Mastoid breadth
Col. F: Interorbital constriction
Col. G: Length of maxillary tooth-row
Col. H: Breadth across upper molars

==========================+======+======+======+======+=====+=====+=====
A | B | C | D | E | F | G | H
--------------------------+------+------+------+------+-----+-----+-----

_Sturnira ludovici occidentalis_, holotype
92798 KU, (Female) | 42.5 | 22.0 | 12.5 | 11.4 | 5.3 | 6.1 | 7.5
--------------------------+------+------+------+------+-----+-----+-----

1/2 mi. W Revolcaderos, Durango
5698 MSU, (Female) | 43.7 | 22.6 | 13.1 | 11.9 | 6.0 | 6.3 | 7.8
5699 MSU, (Female) | 42.3 | 22.2 | 12.7 | 11.3 | 5.6 | 5.9 | 7