248 BULLETIN 57 , UNITED STATES NATIONAL MUSEUM. 
lower canines in contact with each other or separated by a narrow 
space. Upper premolar large, its crown area slightly more than half 
that of first molar, its antero-internal cusp well developed. Lower 
premolars closety crowded, the anterior much smaller than posterior, 
the crowns of both teeth wider than long, and slightly crescentic in 
outline. Molars strictly normal, m 1 and m 2 with hvpocone obsolete 
though obviously indicated, m 3 with second commissure always well 
developed, and a small third commissure sometimes present ; m - 
and m 2 with low protoconid and large, long entoconid, m with 
protoconid obsolete, and entoconid smaller than Irypoconid. Skull 
(figs. 39 and 40) broad and flattened, the rostral portion marked 
by conspicuous lachrymal 
ridges, but sagittal crest 
obsolete; lachrymal 
breadth distinctly greater 
than length of rostrum, 
which in turn is about two- 
thirds that of brain case; 
depth of rostrum dis- 
tinctly less than that of 
brain case; antorbital fo- 
ramina opening very con- 
spicuously forward at bot- 
tom of groove formed be- 
tween side of rostrum and 
high lachrymal ridge; pal- 
ate distinctly arched, and 
slightly domed, its ante- 
rior portion entire or with 
two minute foramina; ba- 
si sphenoid pits obsolete or 
absent ; audital bullse 
strongly emarginate on inner side as usual in the family. External 
form thickset and heavy, much like that of Eomops. Ear short, 
orbicular, extending somewhat more than halfway from eye to nostril 
when laid forward; keel low but distinct; tragus small, narrowed 
above; antitragus well developed, but not thickened; anterior termi- 
nation of ear on forehead close to that of opposite side. Lips much 
thickened, but not specially expanded or wrinkled, the upper lip 
sprinkled with spoon hairs, particularly in front. Muzzle pad indis- 
tinct, without definite ridges. Legs, feet, and tail thick and heavy. 
Membranes leathery. 
Species examined. — Molossops cerastes (Thomas), M. paranus 
Thomas, M. planirostris Peters, M. temminckii (Burmeister). 
Remarks . — Both externally and in the structure of the skull this 
