hat may be named and
described as follows:

MYOTIS NIGRICANS DALQUESTI new subspecies

_Type._--Male, adult, skin and skull, No. 23839 Museum of Natural
History, University of Kansas; from 3 km. E of San Andres Tuxtla, 1000
ft., Veracruz; obtained on January 5, 1948, by Walter W. Dalquest,
original No. 8444.

_Range._--Tropical Life-zone of eastern Mexico from southern Tamaulipas
to central Chiapas.

_Diagnosis._--Color black or dark brown, venter having brownish wash;
size large (see measurements); M1 and M2 quadrangular; prominent
protostyle on P4; P2 and P3 in straight line; sagittal crest absent.

_Comparison._--Color almost as in _Myotis nigricans extremus_, the
subspecies occurring adjacent to _dalquesti_ in Chiapas and Tabasco.
From _M. n. extremus_, _dalquesti_ differs as follows: larger; hypocone
in M1 and M2 broader making posterointernal part less rounded;
protostyle of P4 prominent instead of absent; P3 in line with C and P2
instead of displaced lingually; sagittal crest absent instead of present
posteriorly. _Myotis nigricans nigricans_ and _M. n. dalquesti_ are of
approximately equal size; otherwise they differ in the same features as
do _extremus_ and _dalquesti_.

_Measurements._--Average and extreme measurements of seven males from
the type locality, followed by those of 19 females from 38 km. SE Jesus
Carranza, and finally length of forearm and cranial measurements of
eight female topotypes of _M. n. extremus_, are as follows: Total
length, 80 (77-82), 76 (72-80); length of tail, 32.8 (30-35), 33.5
(31-35); hind foot, 7.9 (7-8), 8.0 (8-8); forearm, 34.2 (33.6-35.3),
35.1 (33.1-36.4), 33.1 (31.8-34.3); greatest length of skull (including
incisors), 13.8 (13.3-14.1), 13.6 (13.2-14.1), 12.9 (12.6-13.1);
zygomatic breadth, 8.1 (7.9-8.4), 8.1 (7.9-8.3), 8.0 (only one can be
measured); width of rostrum above canines, 3.2 (3.1-3.3), 3.2 (3.0-3.4),
3.1 (3.0-3.2); interorbital constriction, 3.6 (3.5-3.7), 3.6 (3.5-3.8),
3.4 (3.3-3.4); occipital depth (excluding auditory bullae and sagittal
crest), 4.6 (4.4-4.8), 4.6 (4.3-4.9), 4.3 (4.1-4.6); maxillary tooth-row
(C-M3), 5.0 (4.8-5.1), 5.0 (4.8-5.2), 4.7 (4.6-4.8); maxillary breadth
at M3, 5.2 (5.1-5.4), 5.3 (5.1-5.5), 5.1 (4.8-5.2).

[Illustration: FIG. 1. Left side of skull, incisors, canine, and
premolars x 11, and occlusal surface of left first upper molar x 20. A.
_Myotis nigricans dalquesti_, holotype. B. _Myotis nigricans extremus_
No. 77674 USN