47 
like that of Pteropus and of Pachysoma, but rather more pointed, 
less angular, and having anteriorly a very canine-like appearance. 
The remaining teeth—restricted to two in number—are small and 
feebly developed, the hinder one the smaller of the two. The third 
or hinder one, which in Péteropus was but rudimentary, is here quite 
lost, and the one nearest to it has undergone a degradation in deve- 
lopment corresponding with that of the one in Pteropus, which is 
absent. : 
Lower jaw.—In Pteropus we find in the lower jaw, omitting the 
incisors and canines, first a small and tubercular pre-molar, not often 
absent ; second, a large and prominent pre-molar, shaped like the 
long one in the upper jaw; and third, another similar in form to the 
last, but less prominent. Three other teeth complete the number, 
and they gradually decrease in size to the hinder one, which is a mere 
tubercle with a flattened crown. The fourth tooth from the canine 
or the third one counting from behind, occupies the place proper for 
the carnassier, but that tooth exhibits no peculiarities of form. Re- 
verting for comparison to Pachysoma, as before, the difference which 
we find in the dentition of the lower jaw from that of Pteropus assists 
in the numeration of the different kinds of teeth of the latter. We 
find the small anomalous pre-molar followed at a considerable interval 
in some of the species by a prominent and rather pointed tooth. 
Then comes another interval, followed by three teeth, the first of 
which is considerably longer than the other two, and more pointed 
It has somewhat of the carnassial form, and is placed in the position 
proper for that tooth in relation to the two molars, whilst the tooth 
in front of it is here separated from those on either side like an ordi- 
nary pre-molar. The same dentition obtains in the lower jaw of 
Epomophorus, with this difference, that both molars are greatly re- 
duced in size, being scarcely more than rudimentary. 
From this it would appear that the Frugivorous Bats form an ex- 
ception to the law which regulates the variation in the dentition of 
the Insectivorous ones, in which the true molars are liable to but 
slight variations in number or form, and in which the pre-molars 
suffer considerable modifications, not merely in the several genera, 
but even in the different species in the same genus. It is possible 
that the pre-molars may be in reality absent in this group, and their 
places taken by modified true molars, and by this means the proper 
number of the latter preserved. But this is rendered improbable, if 
not actually disproved, by the fact that the absence in one genus 
(Pachysoma) of the third true molar is predicted by its rudimentary 
condition in another (Pteropus), in which the proper number of true 
molars certainly exists. And this partial development of the molar 
‘series may be traced yet further in those genera which have lost the 
third molar, and in which the second molar has assumed in some 
measure the abnormal form and size of the third or missing one. 
Besides the abridgment in number, and imperfect development of 
the molar teeth, the cranium of Epomophorus exhibits certain other 
peculiarities worthy of note. It is altogether a fragile structure, 
the upper maxillary bones in some of the species being so thin and 
