310 
By the vertebra found at Seichem, which appeared to be of one 
and the same spine, and by the memoir of M. Herman, M. Cuvier 
found himself able to determine the absolute number of the vertebra 
of each sort. 
The number of the vertebra of the neck, back, and loins, without 
reckoning the atlas and axis, he concludes to have been twenty-nine ; 
and supposing the two last of the number to have belonged to the 
pelvis, they would be twenty-seven, precisely the same as in the 
monitors, in which animal, four of the neck, and two ol the loins, are 
without ribs. There are, therefore, in the monitors, twenty -three pair 
of vertebral ribs ; whilst the crocodiles have but seventeen, even when 
counting the five little false cervical ribs ; and it is very probable that 
the fossil animal had twenty-two or twenty-three at the least. 
The number of the vertebra of the tail appears to have been ninety- 
seven. This number much exceeds that of the crocodile, which has 
but thirty-five : but they very little exceed those of the monitor, M. 
Cuvier having found seventy-nine caudal vertebra in a skeleton of 
this animal, in which some were known to be wanting. 
The length of the cervical, dorsal, and lumbar vertebra;, appears to 
have been about nine feet five inches, and that of the vertebrae of the 
tail about ten feet ; adding to which the length of the head, which 
may be reckoned, considering the loss of the intermaxillary bones, at 
least at four feet, we may safely conclude the whole length of the skele- 
ton of the animal to have approached very nearly to twenty-four feet. 
The head is a sixth of the whole length of the animal ; a proportion 
approaching very near to that of the crocodile, but differing much 
from that of the monitor, the head of which animal forms hardly a 
twelfth part of the whole length. 
The tail must have been very strong, and its width at its extremity 
must have rendered it a most powerful oar, and have enabled the ani- 
mal to have opposed the most agitated waters, as has been well re- 
marked by M. Adrian Camper. From this circumstance, and from 
