ON ARCTOCEBUS CALABARENSIS 593 
a smaller bird-like tongue, which springs from the franum, and pro- 
jects forwards about {ths of an inch in length, reaching to within 
tth of an inch of the point of the tongue itself. This horny lamina 
measures about }th of an inch in breadth across its root or base, and 
about gth 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, 
projecting along the sides of the gums of the lower jaw, in which, 
apparently, 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 vertebre piercing through the 
horny integument of the back, with a weak horny covering, as 
described by Van der Hoeven of the Szenops 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 {th of an inch broad at its base, which projects about {th 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 $th 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 ¢iree. 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 
¥OL., 11, QQ 
