A New Bat (Myotis) From Mexico

Myotis elegans new species

Holotype.—Female, adult, skin and skull, No. 88398 Museum of Natural
History, The University of Kansas; 12-1/2 mi. N. Tihuatlán, 300 ft. elevation,
Veracruz, Mexico; obtained on September 24, 1961, by Percy L. Clifton,
original No. 985.

Geographic distribution.—Known only from the type locality.

Diagnosis.—A small-footed species having a short tail and small skull.
Pelage on upper parts near (16' l) Prout's Brown (capitalized color terms after
Ridgway, Color Standards and Color Nomenclature, Washington, D. C., 1912),
and more golden on underparts; ears pale brownish and flight-membranes
only slightly darker; thumb small (7.5 mm. including wrist); tragus slender
but deeply notched. Longitudinal, dorsal profile of skull relatively straight
but frontal region elevated from rostrum and lambdoidal region elevated from
posterior part of parietal region; posterior margin of P4 (in occlusal view)
notched.

Comparisons.—Among named kinds of Myotis, M. elegans shows most resemblance
to the species M. californicus and M. subulatus. Differences from
the latter include shorter tail and ear, more golden color on underparts, pale
(not blackish) lips, ears and flight membranes, more slender tragus, shorter
skull, posterior border of P4 (in occlusal view) more deeply notched, and
longitudinal dorsal profile of skull higher in frontal and lambdoidal regions.

Differences from M. californicus include shorter tail, more golden color on
underparts, deeper notch in tragus, shorter skull, notched instead of smooth
posterior border of P4 (in occlusal view), longitudinal, dorsal profile of skull
less abruptly elevated in frontal region and with (instead of without) prelambdoidal
depression. From M. c. mexicanus that occurs to the north, west,
and south of the type locality of M. elegans the latter further differs in darker
color, paler ears, paler flight membranes, and lesser size, including skull.

Differences from M. nigricans of the same region include reddish instead
of black pelage, smaller hind foot, smaller skull, rostrum smaller in relation
to remainder of skull, narrower interorbital region, and absence of a sagittal
crest.

Measurements.—Total length, 79; length of tail, 34; length of hind foot,
7.5; length of ear from notch, 12; length of tragus, 6.5; weight, 4 grams; length
of forearm, 33.0; greatest length of skull, 12.4; condylobasal length, 11.9;
interorbital constriction, 3.2; breadth of braincase, 6.1; occipital depth, 4.5;[Pg 164]
length of mandible, 8.9; length of maxillary tooth-row, 4.6; maxillary breadth
at M3, 4.9; length of mandibular tooth-row, 5.0. Degree of wear on teeth,
stage 2 (in terminology of Miller and Allen, Bull. U. S. Nat. Mus., 144, May
25, 1928).