﻿No. 13. NORTH AMERICAN FAUNA. October, 1897. 



REVISION OF THE NORTH AMERICAN BATS OF THE FAMILY 



VESPERTILIONID.E. 



By Gerrit S. Miller, Jr. 



Writers on American bats have published a large mass of facts con- 

 cerning the distribution and comparative anatomy of members of the 

 family VespertiUonidce. Unfortunately, however, no work has yet 

 appeared in which the numerous species by which this group is now 

 known to be represented in North America^ are treated from the stand- 

 point of the systematic zoologist. In other words it has hitherto been 

 impossible for anyone not thoroughly acquainted with the extensive 

 and scattered literature of Korth American bats to identify specimens 

 correctly. The present paper has. been prepared with special reference 

 to the long-felt want of a ready means to accomplish this object. 



MATERIAL. 



The greater part of the material on which this revision is based is 

 contained in the collection of the Biological Siirvej' of the U. S. Depart- 

 ment of Agriculture. This collection of bats, which consists of more 

 than 3,000 specimens, chiefly in alcohol, has been brought together dar- 

 ing the past few years by the held naturalists of the Survey. In addition, 

 the writer has examined the bats in the United States National Museum,, 

 the American Museum of Natural History, and several private collec- 

 tions, making a total of about 2,700 specimens of North American 

 VespertiUonidw. It is to be regretted that so few South American bats 

 are contained in the museums of the United States that no definite con- 

 clusions can be reached concerning the relationships of several Mexican 

 Species to the forms occurring farther south. For this reason certain 

 questions of nomenclature must for the present remain in a condition 

 of uncertainty. It is also to be regretted that comparatively few well- 

 prepared skins are available for comparison. Without good series of 

 dry specimens it is impossible to determine the limits of individual 

 variation in color, as conclusions of the most general kind only can be 

 based on specimens that have been subjected to the action of alcohol. 

 Series of bat skins as extensive as those by which most groups of small 

 North American mammals are now represented will doubtless prove 



iln the present paper tlie term North America Is used to indicate the whole of the 

 North American continent and the West Indies. 



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