Chapter 2

Published December 29, 1961

UNIVERSITY OF KANSAS Lawrence, Kansas

PRINTED BY JEAN M. NEIBARGER, STATE PRINTER TOPEKA, KANSAS 1961 [Device] 28-8477

A New Subspecies of the Black Myotis (Bat) From Eastern Mexico

BY

E. RAYMOND HALL AND TICUL ALVAREZ

In 1928 when Miller and Allen (Bull. U. S. Nat. Mus., 144) published their revisionary account of American bats of the genus _Myotis_, the black myotis, _Myotis nigricans_, was known no farther north than Chiapas and Campeche. Collections of mammals made in recent years for the Museum of Natural History of The University of Kansas include specimens of _M. nigricans_ from eastern Mexico as far north as Tamaulipas. Critical study of this newly acquired material reveals that it pertains to an hitherto unnamed subspecies that 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).

_Remarks._--The subspecific name _dalquesti_ is given in recognition of Prof. Walter W. Dalquest who gathered the largest and most varied collection of mammals ever taken in the state of Veracruz.

Inspection of the measurements given above will reveal that there is no overlap between _extremus_ and _dalquesti_ in the interorbital constriction or occipital depth and only slight overlap in the length of the maxillary tooth-row and maxillary breadth.

In 10 adult females from Ocosingo, Chiapas, there is suggestion of intergradation between _dalquesti_ and _extremus_ in that one specimen (66515 KU) has the cranial characters of _extremus_ except that it is large like _dalquesti_; in two other skulls P3 is slightly displaced lingually and two other skulls bear a slight sagittal crest. These are features characterizing _extremus_. Otherwise the specimens resemble _dalquesti_, to which subspecies they are here referred.

Three males from a place 8 km. W and 10 km. N El Encino, 400 ft., Tamaulipas, are the northernmost representatives of the species and differ from the other specimens of _dalquesti_ in shorter forearm, shorter maxillary tooth-row and lesser maxillary breadth.

Study in the laboratory was supported by Grant No. 56 G 103 from the National Science Foundation. Field work was supported by a grant from the Kansas University Endowment Association. We thank Dr. David H. Johnson for lending eight topotypes of _M. n. extremus_. Other specimens of _extremus_ available to us are as follows: 1 mi. E Teapa, Tabasco, 1 (7535 LSU--courtesy of Dr. George H. Lowery, Jr.); Cayo Dist. Augustine, British Honduras, 1 (9670 KU, in red phase); 12 km. NNW Chinaja, Guatemala, 4.

_Specimens examined._--Total, 142, as follows: Tamaulipas: 8 km. W, 10 km. N El Encino, 400 ft., 5. Veracruz: 4 km. WNW Fortin, 3200 ft., 1; 2 km. N Motzorongo, 1500 ft., 1; 3 km. E San Andres Tuxtla, 1000 ft., 7; 38 km. SE Jesus Carranza, 500 ft., 118. Chiapas: Ocosingo, 10.

_Transmitted June 30, 1961._

28-8477