404 EMBALLONUniDJ?. 



Range. The tropical, subtropical, and warmer parts of the tem- 

 perate regions of both hemispheres. 



Synopsis of the Genera of Molossi. 



a. Fu'st toe mucli larger and thiclier than the 



other toes and separable from them ; ears 

 quite separate. 

 a'. Preniaxillary bones united; upper inci- 

 sors very strong, close together in front 11, Cheihomeles, p. 405. 



b. First and hfth toes much thicker than the 



other toes; ears united or close together 

 b_v their inner margins. 

 b'. Prernaxillary bones united ; upper inci- 

 sors close together in front 12. MoLOSsus, p. 407. 



c'. Premaxillary bones separate, or united by 

 cartilage only ; upper incisors separate 

 in front 13. Nyctinomus, p. 420. 



The genus Cheiromeles is represented by a single species only, 

 which, as I have previously remarked*, appears to be more closely 

 allied to Molossus, which is restricted to America, than to Nyctino- 

 mus, of which several species inhabit the same countries with it. 



The genera Molossus and Nyctinomus are very closely allied, some 

 species, as Molossus c/laucinus, Wagner, and M. bomiriensis, Peters, 

 forming the connecting links between them. Nevertheless I retain 

 these genera distinct, as they are convenient for grouping the species, 

 and partly correspond to their geographical distribution, the species 

 of Molossus being limited to America, while those of Nyctinomus 

 are found in both hemispheres. 



These genera have been divided into several subgenera, which 

 depend on slight differences in dentition and in the form of the ear- 

 conch and tragus. But so many perfectly intermediate forms exist 

 that it is impossible to subdivide Molossus and Nyctinomus, which, 

 indeed, as I have remarked above, may come to be regarded here- 

 after as subgenera only. Thus M. {Promops) ahrasus resembles M. 

 rufus (the representative of the suhgenus Molossus) closely in the 

 form of the tragus and in the obtuse not obliquely truncated muzzle ; 

 and M. {Promops) nasutus, relegated to the subgenus Promops on 

 account of its dentition, in all other respects is much more closely 

 allied to M. ruftis, with which it agrees in the peculiar form of the 

 antitragus and tragus, and even in the distribution of the fur; while 

 31. rufus, which differs from every other species in dentition, shows 

 its close affinity to the representatives of the subgenus Myopterus in 

 the perfectly similar form of its antitragus and in the shape of its 

 muzzle. 



The subgenus Mormopterus is distinguished from Nyctinonitis by 

 the absence of the first minute upper incisor, and by the distinctly 

 separate ears ; but N. norfolcevsis. Gray, is quite intermediate, agree- 

 ing with Nyctinomus in dentition, and in other respects with Mor- 



* ' Monograph of the Asiatic Chiroptera,' p. 177. 



