570 Mr. G. S. Miller, Jr., on a 



Three other species of Mormopterus are known to science, 

 viz., M. albi'veyiter, M. acetabulosus, and M. setiger. The 

 first of these is confined to Madagascar, the second has a 

 •wide range from South-east Africa to Madagascar and 

 ]\rauritius, while the last has been taken in German East 

 Africa. 



M. Whilleyi differs from .1/. alhiventer in being somewhat 

 smaller, in having a well-defined antitragus in the ear-conch, 

 and from all the three in having only four lower incisors 

 instead of six. 



M. Whitley i differs from M. acetabulosus and M. setijer in 

 having the ears close together on the forehead, in the more 

 regularly triangulate shape of the ears, and in the squareness 

 of the tragus. 



Finally, il/. Whitleyi diff'ers from M. setiger in being 

 smaller and in havinor the traijus rounded off above. 



LXXIV. — A new Bat from Peru. 

 By Gerrit S. Miller, Jr. 



Among some Peruvian bats submitted for determination by 

 Mr. Oldfield Thomas there are three spec- mens whose super- 

 ficial appearance is much like that of Pipistrellus hesperus 

 (H. Allen), but whose structural characters show relationship 

 with the members of the genus Rliogeessa. The peculiarities 

 of the ear and teeth, however, are so great that the species 

 cannot be placed in any of the known genera of its family. 



TOMOPEAS, gen. no v. (Vespertilionidce) . 



Type Tomopeas ravus^ sp. nov. 



Characters. — Similar to Ehogeessa, H. Allen, except that 

 there are only four incisors in the mandible and the structure 

 of the ear is essentially like that of the small-eared species of 

 Nyctinomus. Ear-conch provided with a distinct though 

 rudimentary keel occupying the same position as in the 

 members of the family Molossid^. Anterior border of ear 

 terminating simply, and without trace of basal lobe or ''hem." 

 Tragus low and rounded, no larger than in some of the 

 species of Nyctinomus, and barely visible in the dried skin. 

 Nostrils distinctly short-tubular. Upper lip broad and 

 spreading. 



Dental formula : i. ^^, c. yzii, pni. ^E^, m. 3^=28. 



