170 On the Natural History of the Dugong, 
Such is the amount of evidence that I am at present able to 
obtain. é 
It is very apparent that the whole of the specimens may be re- 
duced to two classes, according to the differences in their tusks, 
the molares, cwi. par. being the same in all the individuals. Thus 
we have lst, Those whose tusks (as in No. 1, 2, 36,5, and 7,) pro- 
ject 1 inch or 12 inch beyond the bony sockets, diverging outwards, 
and whose external margin is worn to a flat surface: these teeth 
are hollow to a great extent from the extremity of the root. And 
2dly, Those (as No. 3a, 4, and 6,) whose tusks do not protrude 
from the sockets in any degree sufficient to fit them for use: they. 
are not hollow, but are terminated at the root by a crested cup. 
Moreover they are much straighter, rounder, and less compact in 
their general structure than the former. 
Hence the question has arisen, are these diversities owing to dif- 
ference of age? or do they constitute the characters of distinct va- 
rieties or species ? 
by two obstacles which are at present insuperable. Ist, Because, as the Pro- 
fessor on one occasion stated, “‘ the Royal Commissioners have not yet authorized” 
him to throw open the osteological museum ; and 2d/y, Because it is the Pro- 
fessor’s “ private property,” and I might as well “ go into his drawing-room,” as 
he recently remarked, with a degree of the fortiter in modo, when, in consi- 
deration of the absorbing engagements which he placed in the way of my ad- 
mission, I inquired of him “ Whether there were no other means of obtaining 
access to that museum, without giving him the trouble to attend me ?” 
I am concerned that the same cause should have prevented me from obtain-. 
ing accurate notes on the osteology and general developement of a young spe-_ 
cimen of the dugong, (not much above half the size of the adult,) which is also: 
deposited in the College Museum. There is a confused stery of its having 
been sent home by the Duke of Manchester when governor of Jamaica; but it 
must not on that account be supposed that the animal is a manatee; for it 
has been also said, that the specimen came from the East, and the distinctive 
characters of the dugong are sufficiently evident. The skeleton is in an imper-- 
fect condition, being without the sternum, and having its mouth adorned with a 
most heterogeneous collection of teeth of horses, &c. and fragments of ivory. 
There are, however, most of the molar teeth remaining, five on each side of 
both the jaws being the original number. In the upper jaw, the posterior _mo- 
lar has its crown tuberculated, and very little advanced from the socket ; and 
in the lower maxilla, the corresponding tooth has not yet passed out from its 
bed; the other molars have smooth crowns from use: the anterior are the > 
smallest. 
In the Phil. Trans. (1820, P. 315. and 182], Pl. 20.) there is a description, _ 
with figures, of the skeleton and general anatomy of a young dugong, 4 feet 
6 inches long, which was also sent to Sir E. Home by Sir S. Raffles, who, it is 
but justice to say, has done every thing in his power to increase our knowledge. 
of this animal. It had two incisores in the upper jaw immediately before the 
tusks, and more advanced in the gum than these teeth. The gum covering the 
alveoli was very thick, and a ligamentous substance passed down from it into 
each separate opening, and attached itself to the teeth they contain. There 
were twenty (temporary) molars, five on each side of each jaw. 
*¢ In the anterior scabrous projection of the lower jaw, were four regular - 
sockets on each side, filled with a ligamentous substance passing inte them. 
trom of sey forming gubernacula for the incisores not yet completely form-; 
ed,” (p. 316. 
The mangled condition of the bones in the College Museum, prevent the de- 
tection of these two superior incisores ; but it seems to be the fact, that, as Dr. 
en has remarked, ‘ they are shed at an early period, and not replaced:by. 
others.” 
