166 BULLETIN 51, UNITED STATES NATIONAL MUSEUM. 
In general like Ardops , but skull with nasal region much depressed 
between high supraorbital ridges; anterior nares directed chiefly 
upward and extending fully halfway from front of premaxilla- 
ries to point of juncture of supraorbital ridges which are not angu- 
lated at middle, but extend in a nearly straight line from front 
of orbit to sagittal crest; incisive foramina separated from roots 
of incisors by space equal to their greatest diameter; inner upper 
incisor with high slender crown, as in Phyllops; first and second 
upper molars with low but distinct metaconule on surface of crown 
between hypocone and metacone. 
Species examined. — This genus is known from the published de- 
scriptions and figures only, as a second specimen has not been taken 
and the type is now lost. The details in Wagner’s lithograph of 
the skull published by Peters are so complete as to leave no doubt 
that the animal represents a peculiar genus, characterized particu- 
larly by the form of the rostrum and the presence of the well-devel- 
oped metaconule in the first and second upper molars. These pecul- 
iarities make it the most aberrant member of the restricted Steno- 
dermine group. 
Genus PYGODERMA Peters. 
1863. Pygoderma Peters, Monatsber. k. preuss. Akad. Wissensch, Berlin, 
p. 83 (subgenus of 8 denoderma) . 
1865. Pygoderma Peters, Monastber. k. prenss. Akad. Wissenscb., Berlin, 
p. 357 (genus). 
1878. Pygoderma Dobson, Catal. Chiropt. Brit. Mus., p. 536 (genus). 
, Type- species. — Stenoderma microdon Peters. 
Geographic distribution. — Warmer parts of America north to 
southern Mexico. 
Number of forms. — Two species of Pygoderma are known — the 
type, and the better known, P. bilabiatum Wagner. 
Characters. — Dental formula : 
-2 3 . 1 . --345 6- . 2-2 
1 2 -. 1 . - 2.-4 5 6 - 2-2 
c 
1-1 
1-1 
,jpm 
2-2 
2 - 2 ’ 
m 
2-2 
2-2 
= 28 . 
Upper incisors very unequal, forming a continuous row between 
canines; the inner large, nearly half as high as canine, conical, 
slightly higher than long, in contact basallv, their tips wide apart, a 
faintly suggested secondary cusp near middle of outer side ; the outer 
minute, nearly flat-crowned, barely extending to cingulum of canine. 
Lower incisors very small, closely crowded in a straight line between 
canines, their subequal crowns deeply grooved transversely to the 
tooth row. Canines low, stout, with prominent cutting edges and 
wide postero-internal heel, which, in mandibular tooth bears a dis- 
tinct secondary cusp; in both mandibular and maxillary tooth the 
cingulum is moderately developed, forming a minute posterior cusp. 
