1902. _Molossus nigricans_ Miller, Proc. Acad. Nat. Sci.
Philadelphia, 54:395, September 12, type from Acaponeta,
Nayarit.
_Distribution in Tamaulipas._--Southern part of state, north
at least to Guemes.
At Rancho Pano Ayuctle, according to the field notes of the collector
(Schaldach), the red mastiff bat was common, and found daytime retreats
in hollows in cypress trees. Schaldach twice found groups of bats in
such hollows. _M. a. nigricans_ is an early forager and most
individuals seen were in flight before sunset, usually flying in a more
or less straight line at heights of 25 to 60 feet above the ground. The
odor of the chest gland was described by Schaldach as "strong" and
"geranium-like." A female obtained three miles northeast of Guemes on
August 19 carried a single embryo that was 33 mm. in crown-rump length.
Specimens examined average slightly smaller than the type specimen,
especially in total length, length of hind foot, length of skull and
length of maxillary tooth-row. Davis (1951:219) also noted some of
these same differences in a specimen examined by him from two miles
south of Ciudad Victoria. The variation in color is great among
Tamaulipan specimens. Of the 15 examined, two are Dark Mummy Brown, six
are Mummy Brown, six are Sudan Brown, and one is paler than Sudan
Brown.