46 NORTH AMERICAN BATS. 



VESPERTILIO, Keyserlixg & Blasius. 

 Vespertilio, Keyserlixg & Blasius, "Wirbel tliiere Europas, 1840, 17. 

 Molars f ; skull inflated, raised above the line of the nasal 

 bones ; internal basal lobe of ear sharply defined, more or less 

 acute. 



Fig. 41. 



Y. subnlatus. 



The term Vespertilio has been variously applied by authors. 

 As employed by Linnaeus, it represented a group now considered 

 to be an entire order — Cheiroptera. When Geof. St. Hilaire 

 revised the bats, he restricted the name to the naked-nosed forms 

 with the tail inclosed within the interfemoral membrane. It 

 has again been divided by numerous authors, among whom may 

 be mentioned Isidore GeofiVoy, Temminck, Gray, Keyserling & 

 Blasius, until at present as properly restricted by the latter 

 accomplished naturalists, it is used to designate a small but well 

 defined group, the members of which embrace the most delicate 

 forms of Vespertilionidse. Owing to the fact that species of the 

 genus have a widely spread distribution, minute difi"eronces in 

 form and color in specimens brought from distant localities have 

 been made of more importance than they deserve. Species have 

 thus sprung up, many of which have never been identified, and 

 serve only to retard progression by a useless synonymy. 



Some of the many so-called species of this country I have been 

 enabled to determine ; with others, however, I have not been so 

 successful. The names of the former are mentioned as synonyms 

 to those having the priority. With the remainder I am obliged 

 to content myself with merely naming, viz. : V. subflavus, V. 



