2 PROCEEDINGS OF THE NATIONAL MUSEUM VOL.78 



real status of T. aurispinosa, the type and only known specimen of 

 which has no skull. The differences in this skin from skins of T. 

 laticaudata are very slight. 



It might be well to observe here that the type of Nyctinomus 

 orthotis proves to be a Eumops ^ and that Nyctinomus kalinowskii is 

 now placed in the genus Mormopterus} 



All specimens of the genus Tadarida in the American Museum of 

 Natural History, New York City, as well as all South American 

 specimens of the genus in the Field Museum of Natural History, 

 Chicago, have been examined. Specimens listed, that are not followed 

 by abbreviations, are the property of the United States National Mu- 

 seum. The abbreviations F. M. stand for the Field Museum, 

 Chicago, and A. M. N. H. stand for the American Museum of Natural 

 History, New York. My thanks are extended to Mr. H. E. Anthony, 

 of the American Museum of Natural History, New York City, and to 

 Dr. W. H. Osgood, of the Field Museum of Natural History, Chicago, 

 for the loan of specimens under their charge. 



KEY TO THE AMERICAN BATS OF THE GENUS TADAEIDA 



First or brasiliensis group. — Second phalanx of fourth finger long, 6.6-9.2 mm.; 

 ears extending to or falling short of end of rostrum when laid forward, inner 

 edges not united at base; slight indication of pocket in membrane at the angle 

 of femur and tibia; skuU with broad flat rostrum, considerably wider anteriorly 

 than at point of least interorbital breadth; weak sagittal crest; upper incisors 

 strongly converging at tips. 



Ear not reaching end of rostrum when laid forward. 



Total length of skull 17.0 mm. or over cynocephala, p. 7 



Total length of skull always under 17.0 mm. 



Forearm 40.0-42.5 mm murina, p. 9 



Forearm 36.6-41.4 mm antillularum, p. 10 



Ear extending to end of rostrum when laid forward. 



Total length of skull never over 16.2 mm.; transverse area of maxillary 



teeth smaller intermedia, p. 7 



Total length of skull always 16.2 mm. or over; transverse area of maxil- 

 lary teeth larger. 



Forearm frequently under 40.0 mm muscula, p. 9 



Forearm always 40.0 mm. or over. 



Breadth at m^ frequently reaching 7.0 mm. 



Forearm 42.2-46.4 mm brasiliensis, p. 3 



Forearm 41.6-43.8 mm constanzae, p. 10 



Breadth at m^ always less than 7.0 mm. 



Color lighter, verona brown bahamensis, p. 8 



Color darker, mummy brown mexicana, p. 4 



Second or macrotis group. — Second phalanx or fourth finger short, 2.0-4.4 mm.; 

 ears extending well beyond end of rostrum when laid forward, inner edges 

 united at base for about 2 mm.; well-developed pocket in membrane at angle 

 of femur and tibia; skull with slender rostrum, scarcely wider anteriorly than 



• Miller, Proc. Biol. Soc. Washington, vol. 19, p. 85, May 1, 1906. 



• Miller, Bull. U. S. Nat. Mus., 57, p. 254, 1907. 



