186 bulletin: museum of comparative zoology. 



Although Chilonatalus and Natalus have not hitherto been found 

 inhabiting together the same island, the fact that the former is found 

 in Jamaica, Cuba, and the Bahamas, while the latter occurs on the 

 intermediate island, San Domingo, and in the Lesser Antilles, is 

 evidence that the two genera reached these islands already fully 

 differentiated, and that Chilonatalus is not to be considered the 

 representative of Natalus in the islands where it is now known. 

 More likely the continental prototype of Chilonatalus was a Central 

 American bat that has since died out. Moreover, the presence in 

 Cuba of the peculiar genus Nyctiellus, occurring here at the same 

 time with Chilonatalus, suggests that it is a derivative of Natalus. 

 Undoubtedly Chilonatalus reached the Greater Antilles by land 

 connection from Honduras to Jamaica, and either thence, or by way 

 of Yucatan, to Cuba, and eastward to the Bahamas. Its presence 

 on Old Providence Island is further evidence of the former land- 

 bridge between the Honduras peninsula and Jamaica. 



The Vespertilionidae offer several peculiarities of distribution. 

 The absence of Myotis from the Greater Antilles has already been 

 noted, and is readily to be explained from the fact that none of the 

 North American species is known to range quite far enough south to 

 have enabled it to spread on to the Yucatan promontory, and so to 

 the Greater Antilles, at such time as a land connection existed. At 

 all events it can hardly be doubted that at that period none of the 

 North American species had extended quite far enough to the south 

 to enable them so to cross. On the other hand, the tropical species 

 M. nigricans had reached the Lesser Antilles from South America, 

 and is now known from Dominica, where it has become slightly 

 differentiated (dominicensis) . Since the species ranges north into 

 southern Mexico (Chiapas), its presence might be expected in Jamaica; 

 but the fact that it has not yet been discovered there indicates that 

 it may only recently have extended to Mexico. 



The genus Eptesicus is known from Cuba and from New Providence 

 in the Bahamas. On the former island is the large, richly colored 

 race cubensis, closely related to E. fuscus miradorensis of Mexico 

 and Guatemala. This fact indicates that the Cuban bat reached 

 that island by way of the Yucatan connection, rather than from 

 Florida. With this conclusion in mind, the occurrence of the very 

 small E. f. bahamcnsis in New Providence, Bahamas, is somewhat of 

 a surprise, in view of the large size of the tropical miradorensis and 

 cubensis. May it not be possible that the Bahama brown bat is an 

 offshoot of the small E. propinquus, found in Guatemala and Nicara- 



