the anatomy of the dugong. 321 
The kidneys are long narrow conglobate, and have eleven 
mammas on each side. 
The form of the penis is represented in Plate XXX. ; it has 
no bone in it, as in the hippopotamus and sea otter. This re- 
presentation is taken from that of the dugong eight feet long. 
The vagina is four inches long. The os tineas takes on the 
form of a rose. The uterus is about three inches long. The 
horns go off at right angles, as in the engraving, (PI. XXX. ) 
which was taken from a drawing of the dugong four feet six 
inches long. 
The cribriform plate of the ethmoide bone in the small 
skull, had three distinct foramina on each side, for the bran- 
ches of the olfactory nerve. 
The eye had a membrana nictitans. The cornea was 
prominent ; the lens double convex, the coats thin, the nigrum 
pigmentum very black. 
The sternum in the small dugong was ligamentous in the 
middle, where the cartilages of the ribs joined it. This pe- 
culiar structure, which appeared to be for the purpose of 
allowing the body to bend forward, was not met with in the 
large one, the whole being formed into one bone. The appear- 
ance is so remarkable, that it is shown in Plate XXXI. 
The two bones in the flesh, substitutes for a pelvis, are 
shown in Plate XXXI.; they were situated opposite the fourth 
vertebra of the loins. 
There is a bony canal in the anterior part of the spine, 
from the anus to the tail, for the great blood vessels, the 
spinous processes of which are only attached to the vertebra 
by ligament. 
There is only one bone corresponding to the phalanges of 
the thumb, and it is the same with respect to the little finger ; 
