18d7.] PKOCEEDINGS OF UNITED STATES NATIONAL MUSEUxM. 515 



A NOTE ON VESPERUaO HESPERUS (ALLEN). 

 By FREDERICK \%\ TRUE. 



Iq his monograph of the bats of i^orth America* Dr. Harrison Allen 

 described, nnder the name of ScotopMlus hes2'>erus, or the Western Bat, 

 a small bat from southern California. His description was based upon 

 four specimens, two of which (Nos. 5509, 5510, Nat. Mus.) were from 

 Posa Creek, and a third (No. 540G, Nat. Mus.) from Fort Yuma. One 

 of these types (No. 5509), with its skull, is still in the national collec- 

 tion. 



Upon examiuiug the skull of this specimen I find that Dr. Allen has 

 apparently mistaken the character of the superior incisors, irf that he 

 describes them as •' of equal length," while in reality the outer pair are 

 only about half as long as the inner pair. Otherwise the skull agrees 

 with Dr. Allen's description, and belongs to the genus Yesperugo of 

 Keyserling and Blasius, and to the subgenus of the same name, as de- 

 fined by Dr. Dobsou. 



The species appears to be distinct and valid. It is, however, men- 

 tioned by Dr. Dobson in his Catalogue of the Chiropterat only in a foot 

 note, and he is apparently doubtful of its validity. After quoting Dt. 

 Allen's description, he writes : " The above description agrees very well 

 with a specimen of a bat from the Straits of Juan de Fuca (Vancouver's 

 Island), which is preserved in the collection of the Hassler Museum, near 

 Portsmouth, and which appears to me to be identical with V. abramus.^' 



At a hiter date this author described a new species of North Ameri- 

 can Vesperugo, under the name of V. merriami, basing his description 

 on a single specimen sent him by Dr. C. Hart Merriam. Upon going 

 over this description with Dr. Allen's type of V. hesperus and another 

 specimen of the same (No. 15981) in hand, I find that the latter agree 

 perfectly with the former. I have no doubt, therefore, that V. merriami 

 must be regarded as identical with V. hesperus (Allen). 



The locality given by Dr. Dobson (Locust Grove, N. Y.)^ is incor- 

 rect. The species is resident in the extreme southwestern section of 

 the United States. Dr. Allen's specimens, as already stated, were from 

 Posa Creek and Fort Yuma, Oal. Another specimen recently acquired 

 by the National Museum (No. 15981), and referred to above, is from 

 Whitewater, San Diego County, in the same State. 



U. S. National Museum, November 21, 1887. 



* Smithsouiaa Misc. Coll., Vol. XI, 1864. t Pages 228-229, foot note. 



