PTEROPUS JAVANICUS. 
surface, The canine teeth are long, erect, grooved, and provided at the base, 
internally, with a semicircular ridge. Of the grinders the first is in most cases only 
rudimentary ; the second, third, and fourth have a similar construction ; their surface 
is greatly compressed. In a lateral point of view, they present anteriorly an elevated 
point, declining to the back part of the tooth, where it constitutes an obsolete notch : 
the anterior elevation is most prominent in the second, and gradually decreases to 
the fourth. Longitudinally their surface is individually divided by a groove, leaving 
on each side an elevated triturating ridge, which has been described above as consti- 
tuting the essential character of tins genus. The fifth grinder is minute, nearly 
triangular, with an even triturating surface. 
In the lower jaw, the front teeth have the same arrangement as in the upper ; 
but the exterior teetli have double the size and thickness of the intermediate teeth. 
The canine teeth are shorter than these teeth in the upper jaw, and they are less 
deeply grooved. The first grinder is minute and cylindrical, having a single 
excavation in the middle of its circular surface. The second, third, fourth, and fifth 
grinders have the same construction as the second, third, and fourth in the upper 
jaw, and the sixth grinder is small, cylindrical, and even on the surface. 
In attempting to define the specific character of the Pteropus javanicus from a 
review of the specimens which I brought from Java, I met with perplexities which 
had not occurred in describing the Pteropus rostratus. These specimens are so 
diversified in their external marks, that they appeared to belong to distinct species ; 
but after the most careful examination, I came to the conclusion, that they indicate 
two strongly marked varieties. One of these corresponds to the specific character 
placed at the head of this article : the second requires a separate description ; and I 
shall only state at present, that the principal distinction consists in a collar of a lighter 
brown, inclining to chesnut, and extending entirely around the neck ; in a mixture 
of brown hairs with the black hairs, both on the back and on the abdomen ; and 
in a more regularly defined line across the back, separating the brown hairs from the 
general black colour of the animal. Of the first variety there are four, and of the 
second five specimens in the Museum. They are sufficiently diversified to shew 
distinctly that the differences are not the effect of age ; and of each variety there are 
young and old specimens. The longitudinal ridge on the summit of the cranium 
affords no distinction, and a careful comparison of the other parts of the skull appears 
to shew that they belong to the same species. The difficulty of discriminating the 
species of this strongly marked genus, in consequence of the uniformity of the 
external marks necessarily employed in defining them, is strongly pointed out by 
M. Geoffroy : it has occurred to me, not only in examining the Pteropus javanicus, 
but also in the review of the individuals of another species, provided with short 
