78 BULLETIN" 144, UNITED STATES NATIONAL MUSEUM 



ously flattened, while in M. austroHparius it is distinctly convex. 

 When the skull is seen from below its general narrowness is evident 

 but there appear to be no structural peculiarities to distinguish it 

 from the skull of M. ludfugus lucifugus. 



Teeth. — The teeth are about the same size as those of Myotis lucifugvs 

 lucifuffti^, therefore smaller than those of M. grisescens and M, velifer. 

 In structure they show no very obvious peculiarities. The upper 

 molars have the full complement of secondary cusps and ridges, and 

 the cingulum on the inner margin of their crowns is almost invariably 

 as much developed as in the maximum condition seen in Myotis lud- 

 fugus (2 exceptions among 16 specimens), a character usually shared 

 by M. grisescens and less frequently by M. velifer. The two upper 

 small premolars are very slightly crowded, the anterior with the 

 transverse axis of its crown perceptibly greater than the longitudinal 

 axis. The anterior tooth is about twice the height of the posterior. 

 The lower canine is relatively short and stout, hardly exceeding the 

 third premolar. The two small anterior lower premolars are fully 

 in the tooth row, the posterior tooth only slightly exceeded in height 

 and cross section by the anterior. 



Measurements. — Foi- measurements see tables, page 80. 



Specvmens examined. — Twenty-three from the following localities : 



?CANADA: 1 skin (B.M.). 



FLORIDA : Tarpon Springs, Pinellas County, 2 skins including type, 4 ale. 

 (A.N.S.P.) ; Bird Key, Tampa Bay, Pinellas County, 12 skins (Copeland). 

 INDIANA: Mitchell, 4 skins (U.S.N.M.). 



Remarks. — Myotis austrariparius bears a general resemblance to 

 several of the brownish species occurring in eastern North America, 

 but may be distinguished by its large and strong hind foot without 

 keel on the calcar, and by its thick, almost wooly fur of a dull cinna- 

 mon or drab tint. In the drab pelage it somewhat resembles the 

 slightly larger Myotis grisescens, but in this species there is no obvi- 

 ous basal darkening of the hairs of the back, and the origin of the 

 wing membrane is from the ankle instead of from the metatarsals 

 near the base of toes. From M. lueifugus, with which it is doubtless 

 often associated, it is distinguished by the lack of noticeable burn- 

 ished tips to the hairs, and by the uniform presence of a distinct 

 sagittal crest on the skull. From Myotis velifer, a species with simi- 

 larly dull unburnished fur, it differs in smaller size, narrow, weak 

 rostrum, and the normal (not enlarged) cheek teeth. From Myotis 

 keenii septentrionalis it is distinguished by its larger feet, less elon- 

 gate ears, and crested skull. 



Although the species was described thirty years ago, its true char- 

 acters are now for the first time recognized. The first specimens re- 



