Ward—The Variations in Proportions in Bats. 
645 
Desmcdus rotundas EL Geoff. 
Nine specimens taken from a small cavern near Zacoalpan 
Amilpas, District of Jonacatapec, Morelos, October 26, 1890, by 
H. L. Ward and O. M T'erax. 
This series is altogether too small to show anything definite 
except that there is a considerable degree of variation in abso¬ 
lute lengths of several of the members and a moderate amount 
of individual variation. Between the length and ear we find a 
complete reversal of proportions, i. e., the shortest individual has 
one of the longest ears and one of the longest individuals has one 
of the shortest ears. Lesser discrepancies occur in comparisons 
of other members. The females appear to rather exceed the 
males in size though this may be only due to an insufficient series. 
Dobson, Oath Chiroptera, Brit. Mus., p. 547, says: “Thumb 
very long and strong, much longer than the foot, . . . ” 
My series of specimens indicates that the foot is equal to or 
longer than the thumb. In Dobson’s diagnosis we also read 
“metacarpal bones of the fourth and fifth fingers progressively 
slightly shorter than that of the middle finger.” In hTo. 502 we 
find that tbe fourth metacarpal slightly exceeds the third. 
This vampire was probably responsible for the depredations 
on our saddle and pack animals that were of almost nightly 
occurrence in central and southern Morelos; for, I believe, no 
other vampire is known to inhabit that region. 
A peculiarity that I have not noted in any other species of 
bat is that its excrement is a thiokish black fluid, very likely 
due to its probably exclusively blood diet. On emerging from 
the shallow cave in which they were taken I found my tan col¬ 
ored boots smeared as if with liquid blacking. 
The time of parturition is probably early in November, for 
No. 499 contained a nearly ripe foetus. The weight of the pre¬ 
served (alcoholic) female was 27.2 gnus, and of the foetus 7.1 
gnus. The species was found in only semi-darkness; but dis¬ 
liked to escape into the strong sunlight outside the cavern and 
so kept circling back and fourth. They bit viciously when 
handled. Four immature specimens were taken at the same 
time. They are not greatly smaller than the: adults in most of 
their measurements; the difference being chiefly noticeable in 
their distal phalanges. 
