110 Proceedings, of the Biological Societi/ of Washington. 
Gener(d characters. — Similar to tyi)ical naso of eastern Brazil, but 
forearm averaging very slightly smaller; sknll much smaller in size; tlie 
anterior upper i^remolar relatively broad with conspicnons cingulum cusp 
anteriorly and posteriorly. 
Color. —Top and sides of the bead and the back a mixture of black 
hairs aud of “ mummy-brown ” hairs with minute white tips, the latter 
becoming more cons|)icuous on the lower hack so as to produce a broken 
whitish hand transversely. The femora and tibiae, the free portion of the 
tail, and the pi’oximal half of the interfemoral membrane clothed with 
rusty hairs (nearly “amber brown” of Ridgway, 1912). At the base of 
the forearm, internally, is a conspicuous patch of short white hair. A 
line of rusty hair borders the ])roximal thii'd or more of tlie iorearm 
externally, beyond which are some four small tufts of whitish and butt 
hairs at 2 or 3 mm. apart. The ventral surface of the body is dull whitish 
slightly washed with huffy ou the l)elly, the hairs everywhere blackish or 
slaty at their bases. A small tuft of whitish hairs is present at the 
anterior base of each ear. 
tS/cull and teeth. —The skull differs strikingly from that of Brazilian 
specimens in its smaller size and narrower rostrum, and relatively longer 
and narrower postorhital region. These ditl'erences though sutiiciently 
apparent to the eye are ditlicult to express in millimeters in so small 
skulls. The anterior upper ])remolar is characteristic. In Brazilian 
specimens, representing time naso, this is a slender lancet-shaped tooth, 
its tip slightly exceeding the cingulum cusp of the canine. It is without 
trace of a cingulum cusp at either side, in some specimens, though in 
others the jiosterior cusp is faintly indicated. The tooth is sei)arated 
from the canine by a sjiace about equal to its own diameter, and from 
the posterior premolar by about twice that distance. In FI. n. prisons 
this tooth is broad, and its crown is in lateral outline nearly an equi¬ 
lateral triangle, the apex of which considerably exceeds the cusp of the 
canine. A conspicuous cingulum cusp is present at both the anterior and 
the posterior ends; while so broad is the tooth that it is nearly in contact 
with the canine. 
MeasurenioUs. —The forearm of the type measures 38.5 mm. In the 
four specimens from the tyiie locality this dimension averages 38.0 mm. 
(37.2-39). In the Brazilian specimens it is very slightly more and 
averages 39.8 in five specimens (38.5-41 ). The following measurements 
are from an alcoholic topotype ( 14,037) and those in parentheses are 
from a specimen from I’oido Segui'o, Brazil, representing true naso: end 
of snout to tip of tail, 53 (58); tail, 13 (13.5); tibia, 14.5 (14.5); hind 
foot with claws, 7.4 (7.3); calcaneum, 19.5 (19.5); forearm, 38.2 (39); 
second metacai-pal, 34 (34); third metacarpal, 37 (30.2); fourth meta¬ 
carpal, 32 (32); fifth metacarpal, 31 (29). 
Skull of the tjipe (and of a Brazilian specimen in parenthe.‘''es): greatest 
length, 12(12.0); basal length, 9.9 (10.3); zygomatic width, 7.2 (7.7); 
mastoid width, 0.5 (0.8); intei’orhital constriction, 2.3 (2.7); upper 
tooth row (front of canine to hack of last molar), 4.0 (5); lower tooth 
row (front of canine to hack of last molar), 4.8 (5). 
