162 OSSEOUS, MUSCULARj AND NERVOUS SYSTEMS 
and the great comparative size of the superior maxillary 
bones, seem to me to have lessened the importance of the 
palate-bones in the formation of the floor of the nostrils, 
and to have reduced the pterygoid processes of the sphe- 
noidal bones to a rudimentary state, by throwing them out 
laterally, so that they are articulated with the upper maxil- 
lary bones by a hinge-like joint, capable of considerable 
motion. They are placed horizontally ; that is, on the 
same line with the osseous palate, and are connected with 
the malleus in the manner described in a former memoir. 
The cranium is articulated to the spinal column by two 
large condyles. The cervical vertebrae are seven in num- 
ber, and thus shew a decided mammiferous character. 
The atlas is very large^ and its processes strongly marked. 
The same observation may be applied to the dentata ; and, 
more particularly, to its spinous processes. The remaining 
cervical vertebrse gradually decrease in size : the develop- 
ment of these vertebrae corresponds with the great strength 
of the muscles which arise from, or are connected with, their 
processes. The total number of vertebrae is forty-nine ; of 
which seven are cervical ; seventeen strictly dorsal, having 
ribs implanted into them ; one lumbar; three sacral, articu- 
lated with the ossa ilii ; and twenty-one caudal. The spi- 
nous processes of the dorsal vertebra are much sloped to- 
w^ards the tail. The four anterior dorsal vertebrse have 
spinous processes on their interior surface, which are 
strong, of a square form, and gently sloped towards the 
neck. The same processes in the last dorsal, in the lumbar, 
and in about one-half the caudal vertebrae, are strong and 
vertical. In the remaining caudal vertebrae, they gradually 
decrease in strength, and slope towards the back. The 
caudal vertebrae strongly resemble those of the beaver, in 
the length and breadth of the transverse processes, and in 
having spinous processes placed on their inferior surface. 
