470 



Bulletin American Museum of Natural History. [Vol. XXXVII, 



Allomops subgen. nov. 

 Text Figs. 12-15. 



Type, Chcerephon (Allomops) osborni sp. nov. 



Supraoccipital border of skull enormously developed in old males, the lambdoid 

 crest high and broad, expanded upward and backward into an oblique overhang, 

 equal in height to about one half the interorbital breadth of the skull, or consider- 

 ably exceeding the width of the foramen magnum, the upper border nearly straight, 

 equal in length to about one half the width of the braincase, with an extension 



Fig. 12. Mops (Allomops) osborni. Skull of type, adult male, No. 49230. \. 



downward from the lateral upper corner on either side to the mastoid process; less 

 developed but strongly indicated in females and young males; sagittal crest weakly 

 developed in the smaller species of the group, very heavily so in the larger forms. 



General form of the skull as in Nyctinomus, the braincase broad and flattened, 

 preorbital furrow or depression conspicuous, but preorbital processes absent; pre- 

 maxillse usually fully ossified on front border, but sometimes emarginate. 



Dental formula: i fEi, c jEj, p fEf (or p 2 being deciduous or wholly absent 

 in some species), m fEf = 30 (or 28). Upper incisors small, about one third the 

 length of the canines, parallel, widely separated from each other and the canines; 



