598 ON ARCTOCEBUS CALABARENSIS 
that I shall describe its dentition at some length, and compare it 
with that of the other Lemurs. 
The series of teeth belonging to the adult dentition is complete 
(except the right outer incisor, which is broken off at the root), and 
the crowns are not at all worn. The total number of the teeth, as 
in the pate of the sae is 36; and the dental formula is— 
7, ; 5 pin.* 3 m2. ae nan 
ti = Wiener ay (A, C, fig. 3) the incisors (2) are set in a nearly 
straight transverse line, at the outer ends of which are the canines 
(c). The distance from the outer 
edge of one canine to that of the 
other is o'4 in. The inner edges 
of the grinders (1-6) are also 
arranged in straight lines; the 
distance of the right and _ left 
series, anteriorly, is o°3 inch, pos- 
teriorly, o'4 ; while the length of 
the series is o'7 inch. The five 
hinder grinders are close together ; 
while the first premolar is separated 
from the second by a slight inter- 
val—less, however, than that which 
separates the first premolar from 
the canine. 
The median incisors are distant 
from one another about ;);th of an 
7 : : inch. The outer incisors are sepa- 
Right dental series of both jaws of 
ites ead pee ott pe rated from them by less than half 
AandC, upper; Band D, lower jaw. that space; but are as near the 
canines as they are to the median 
incisors. The incisors are not more than ,);th of an inch in breadth, 
and are chisel shaped, with their outer angles rounded off. 
The inner and outer incisors are as nearly as possible equal in size, 
and their crowns are not more than jth of an inch long. The 
pointed and curved canines are between 4th and 3th of an inch long, 
and measure ot inch antero-posteriorly. Their front edges are 
convex, the posterior concave, and both are sharp and cutting. 
There is a rudimentary cingulum on the outer side of the base of 
the canine, both internally and externally, and the inner face of the 
tooth is produced into a vertical ridge. The base of each of the 
premolars measures about o'1 inch antero-posteriorly ; viewed from 
without (fig. 3, A) each looks like a shorter canine, with the cingu- 
Tic. 3. 
