THE FAMILIES AND GENERA OF BATS. 
261 
the tooth; a low though distinct hypocone is, however, occasionally 
present. Skull (fig. 49) essentially like that of Promops , but sagit- 
tal crest even more conspicuously developed, and palate merely 
arched — that is, the antero-posterior concavity is much less than the 
lateral concavity. As in Promops and Eumops , the audital bullae are 
much better developed than is usual in the family (the inner margin 
not emarginate), and the basisphenoid pits are distinct. External 
form thick and heavy. Ear as in Promops , except that the antitragus 
is even more constricted at base, suborbicular in outline, and more 
noticeably thickened; tragus minute, subterete. Muzzle and other 
external characters as in Promops. 
Species examined. — Molossus crassicaudatus (Geoff'roy), M. eur- 
rentium Thomas, M. nigricans Miller, M. ob scurus Geoffroy, M. pre- 
tiosus Miller, M. pygmazus Miller, M. rufus Geoffroy, M. tropido- 
rhynchus Gray. 
Remarks. — The genus Molossus is characterized by its short but 
high and 'rounded skull with greatly developed, knife-like sagittal 
crest, arched palate, short upper incisors, and 1-1 lower incisors. 
Externally the only tangible character by which it can be distin- 
guished from Promops is the very minute, subterete tragus, unique in 
the group. 
