322 University of California Publications in Zoology [Vou.17 
based on size and depth of color. But so much of the total area is unrepresented 
by specimens that systematic analysis at this time seems inadvisable. 
Stone (1904a, p. 579) says of two specimens, male and female, of 
Eptesicus fuscus taken at Mount Sanhedrin, California: ‘‘These speci- 
mens are identical with topotypes of HZ. fuscus from Philadelphia.”’ 
Rehn (in Stone, 1904b, p. 590) states that H. f. melanopterus 
which he describes from Mount Tallae 
.is no doubt closest related to f. osceola than any of the form[s] of fuscus. 
The original series of the former has been examined in this connection, and the 
differential characters were drawn from it. The relationship with true fuscus 
is not so close as an examination of a series of thirty specimens from, or within 
a radius of, twenty miles of the type locality shows. No close relationship exists 
with E. f. bernardinus Rhoads, which is a very pale type quite different from 
any of the forms here considered. 
I have examined the type and four paratypes of EF. f. melanop- 
terus, which are in the Academy of Sciences of Philadelphia, and find 
them very nearly uniform in coloration with, and well within the 
range of individual color variation in, series of specimens from else- 
where in the United States and Canada. As Rehn states (loc. cit.), 
the skull is identical with that of the typical form. 
Taking all the above testimony into consideration I feel that the 
subspecifie splitting of Hptesicus fuscus in California is a difficult 
problem, and one which should not be undertaken until abundant 
material is available for comparison, from elsewhere in the United 
States and from the adjoining provinces of Canada and Mexico. 
Genus Nycteris Borkhausen 
This genus ranges from Central America north to the limits of 
tree growth in northern North Ameriea. It occurs also on the Greater 
Antilles, and on the Bahama; Galapagos and Hawaiian islands (Mil- 
ler, 1907, p. 221). Two distinet species are known to occur north of 
Panama, one of which is divisible into at least five geographic races. 
2 lll a ‘1 ee 3-3 
Characters—Dental formula: 1 303" 1 PMo-9> Mg79 = 82. 
Upper incisors only two, short and ee ge oa converging at 
tips; height from cingulum to tip of crown less than twice greatest 
diameter. of tooth. Lower incisors all closely alike, the shafts being 
widely separated and columnar in form; crowns abruptly widened, 
being at their bases twice width of shafts; crowns trilobed and imbri- 
cated; outer pair of lower incisors closely crowded against bases of 
canines. Canines well developed, the upper slightly the larger. 
