316 PROF. HUXLEY ON ARCTOCEBUS CALABARENSIS. [June 28, 
“‘ The external openings of the nostrils are rather lateral, and are 
sinuous, curved upwards and inwards towards the median line of the 
full and rounded snout ; and there is a groove between them running 
down to the front of the upper lip. 
“‘The tongue is long and rounded in front, and rather rough, 
being covered with small papille. Immediately below the tongue is 
the projecting lamina, covered with a horny cuticle and resembling 
a smaller bird-like tongue, which springs from the freenum, and pro- 
jects forwards about 2ths of an inch in length, reaching to within 
+th of an inch of the point of the tongue itself. This horny lamina 
measures about 1th of an inch in breadth across its root or base, and 
about 1th of an inch across its free or front extremity, which is di- 
vided into nine sharp terminal points or filaments............ 
Below the tongue and this supplementary organ the mucous mem- 
brane lining the floor of the mouth has a slightly free margin, pro- 
jecting along the sides of the gums of the lower jaw, in which, ap- 
parently, the ducts of the submaxillary glands (Wharton’s ducts) 
open into the mouth. 
“The neck is rather short and slender. There is no appearance 
on the back of the neck of this specimen of the spinous processes of 
the five last cervical and first dorsal vertebrze piercing through the 
horny integument of the back, with a weak horny covering, as de- 
scribed by Van der Hoeven of the Stenops potto. 
‘«‘ The limbs are very slender and nearly equal in length, the hinder 
extremities being a little larger and stronger in their development than 
the anterior. The fore hands are thinly covered with short hair on 
the dorsal, and are bare of hair, or naked, on the palmar surface. 
The thumb is much larger than any of the other fingers, to which it 
is opposed. There is a large rounded fleshy and horny tubercle, 
nearly jth of an inch broad at its base, which projects about 1th of 
an inch from the base of the thumb on the inner side (near the centre 
of the hand). Immediately opposed to it, and of equal size, or a 
very little larger, is another apparently simple tubercle, rising from 
the outer side (next the thumb) of the base of the clustered fingers ; 
this, however, is the rudimentary index finger, its free extremity 
projecting only about 4th of an inch. It is supported by a short 
metacarpal bone, with a full and rounded extremity, to which are 
attached ¢wo small, or rudimentary, phalanges; each of the other 
fingers (not including the thumb) having three. This rudimentary 
index finger has no nail: there is simply a minute marking like a 
cicatrix, or rather a mere short depressed smooth line, an indication 
of where a nail should be. The nails of the thumb and of the fingers 
are all thin, flat, and rounded or ovate, like those of the human hand, 
and are not extended beyond the points of the fingers. The remain- 
ing three fingers are slender and prolonged, and the first phalanges 
are all conjoined by the integuments, the two distal phalanges of 
each finger, alone, being free. The index or second finger (considering 
the thumb as a finger) is, as already described, merely like a tubercle 
rising at the base of the others. The third finger is the smallest of 
the three other fingers, and also the shortest ; the fourth (or middle 
