6 PROFESSOR ALLMAN ON THE CHARACTERS 
united by their opposed surfaces for the entire length of the first phalanx, a very narrow 
extension of the skin existing at the base of the other digital intervals; the claws are 
of the same form as those of the fore limbs, but are a little longer. The outer edge of 
the sole projects as a narrow membranous border along the whole of the metatarsal 
region. 
The length of the tail, measured from the posterior margin of the vent, is equal to 
the distance from the same point to the middle of the throat. It is so thick at its 
base that the trunk seems uninterruptedly continued into it; but it soon becomes 
laterally compressed, and then grows gradually thinner and narrower towards the tip ; 
immediately in front of the vent it is nearly cylindrical, with a diameter of about 133; 
inch; from this point it gradually thins away, and, at an inch beyond it, its vertical 
height is 13/5 inch, and its breadth ;% inch; while at three inches from the same 
point its height is 1 inch, and its thickness 7g inch; its lower edge is rounded, and 
its upper is continued into a membranous crest of about } inch in height, and clothed 
with the same short, stiff, appressed hairs with which the distal part of the tail is 
covered, 
Teeth_—The determination of the dental formula is not without difficulty. . The incisor 
teeth of the upper jaw (Pl. IL. & fig. 7, p. 10) can be easily ascertained by the limits of the 
premaxillary, whose suture with the maxillary continues very distinct. They will be found 
to be three on each side, though one of them closely resembles a large projecting canine ; 
so also to the first three teeth on each side in the lower jaw the same significance must 
be assigned. A difficulty, however, lies in the tooth which in each jaw succeeds to the 
incisors. In position it is a canine, but in form it isa premolar. It follows close upon the 
third incisor, without the intervention of any distinct diastema; but in the upper jaw it is 
two-fanged, and in other respects is entirely similar to the premolar which follows it ; 
in the lower jaw, however, it is implanted by a single fang, and does not so entirely 
resemble the succeeding premolar as in the upper jaw; this lower tooth passes imme- 
diately in front of the upper one when the jaw is closed, and must certainly be regarded 
as its equivalent. Considering, therefore, that in the upper jaw the tooth in question 
is absolutely similar both in its root and in its crown to an indubitable premolar, 
I believe we may safely regard it and its corresponding tooth in the lower jaw as 
premolars rather than canines; and the dentition of Potamogale will then present 
a series in which the canine teeth are suppressed, and which may be formulated as 
follows :— 
= ae é ye a m 3 Siastiog: 
3-3) °0-0°*" 3-3?" 3-3” 
In the upper jaw the first incisor resembles a canine ; it projects more than any other 
tooth im the jaw; it is conical and pointed, converging above from its base toward its 
fellow, and then diverging below so as to form a curve whose concavity looks outwards; 
it is curved also in another direction, having the concavity looking backwards. The 
