THE FAMILIES AND GENERA OF BATS. 
89 
minute tufts of grayish fur, a character of much use in identifying 
specimens. 
/ Species examined. — Rhynchiscus naso (Wied). 
Genus SACCOPTERYX Illiger. 
1811 . Saccopteryx Illiger, Prodr. Syst. Mamm. et Avium, p. 121 ( leptura ). 
1888-39. U rocryptus Temminck, Van der Hoeven’s Tijdschr. Nat. Gesch. en 
Physiol., V, p. 31 (bilineata ) . 
1878. Saccopteryx Dobson, Catal. Chiropt. Brit. Mus., p. 369 (part). 
Type-species. — V espertilio leptura Schreber. 
Geographic distribution . — Mainland of tropical and subtropical 
America. 
Number of forms . — About half a dozen species of this genus have 
been described. 
Characters . — Teeth as in Rhynchiscus , except that pm 2 is a 
simple terete spicule, and the outer 
anterior cingulum cusp of m 1 is less 
developed. Skull (fig. 14) with 
broad flat rostrum considerably more 
than half as long as brain case, and 
so low posteriorly as £o form a dis- 
tinct angle with forehead. Sides of 
rostrum very slightly inflated and 
median groove obsolete. Lower rim 
of orbit so expanded as to hide tooth 
row when viewed from above. Pre- 
maxillaries large, expanded poste- 
riorly, and terminating on dorsal 
surface of rostrum by an abruptly 
truncate margin. Postorbital proc- 
esses large, broad, and flat. Brain 
case with distinct sagittal crest. Trinidad, no. 6102 ,amer. mus. nat. hist. 
Basisphenoid pits large, well de- x2 - 
fined, separated in middle by a distinct longitudinal plate. Audital 
bulla not as large as area of the pits, slightly but distinctly emar- 
ginate antero-internally. Externally distinguished by the presence 
of a glandular sac opening on upper surface of antebrachial mem- 
brane close to forearm near elbow. The sac is conspicuous in males, 
less developed in females. 
Species examined. — Sac'copteryx bilineata (Temminck), S. leptura 
(Schreber), S. canescens Thomas, S. gymnura Thomas, S. centralis 
Thomas. 
