126 BULLETIN 57, UNITED STATES NATIONAL MUSEUM. 



Genus OTOPTERUS Lydekker. 



1843. Macrotus Gray, Proc. Zool. Soc, London, p. 21. Not Macrotis Reid, 



1837. 

 1878. Macrotus Dobson, Catal. Cbiropt. Brit. Mus., p. 463. 

 1891. Otopterus Lydekker, in Flower and Lydekker, Mammals, living and 



extinct, p. 673. 

 1904. Macrotus H. Allen, Monogr. Bats N. Amer., 1893, p. 33, March 14, 



1894. 

 1904. Macrotus JIilleb, Proc. U. S. National Museum, XXVII, p. 345, 



January 23, 1904. 

 1904. Macrotus Rehn, Proc. Acad. Nat. Sci. Philadelphia, p. 427, April, 



1904, issued June 29, 1904. 



Type-species. — Macrotus ivaterhousii Gray. 



Geographic distribution. — AVarmer parts of middle America from 

 Guatemala to southern California and Arizona, also the Greater 

 Antilles and the Bahama Islands. 



Number of forms. — Eight forms are recognized by Rehn, the most 

 recent writer on the genus. 



Characters. — Dental formula and structure of teeth, essentially as 

 in Micronycteris, but first and second upper molars without hypo- 

 cones, and entoconid of first and second lower molars not as well 

 developed ; paraconid of m ± about as in Micronycteris or slightly 

 more reduced. Skull like that of Micronycteris except that the 

 brain case rises less abruptly in front, forming only a very slight 

 angle with rostrum, the rostrum is distinctly flattened above, and the 

 audital bullae are conspicuously enlarged, covering almost the entire 

 cochlea?, their greatest diameter distinctly greater than the width of 

 the space between them ; basisphenoid pits even less distinct than in 

 Micronycteris. Externally distinguishable from Micronycteris by 

 the even larger ears and by the much longer tail, the extremity of 

 which projects beyond the hinder edge of the broad interfemoral 

 membrane. 



Species examined. — With the exception of Otopterus pygmceus I 

 have examined all the known forms of this genus. 



Remarks. — Although there seems to be no good reason for reject- 

 ing the name Macrotus of Gray on account of the previous use of 

 the same word by Leach as a nomcn nudum applied to the long-eared 

 bat of Europe, or on account of Dejean's Macrotis, 1833, the case is 

 different as regards Reid's Macrotis of 1837. This name is properly 

 defined and is clearly of the same etymology as Gray's Macrotus. 

 1 therefore prefer to adopt Otopterus. 



