288 FOSSIL REPTILES. 



bone, in a fosset for the purpose. Its other extremity unites 

 to the anterior extremity of the junction of the parietal and the 

 OS petrosum. It is nearly parallel to its correspondent bone, 

 and it is between them both that the membranous partitions, 

 which close the cranium in front, commence to approach each 

 other and be confounded in the partition, equally membranous, 

 which separates the two orbits. The bottom of this partition 

 is supported by the prolongation of the anterior and middle 

 apophysis of the sphenoid, which diminishing in thickness and 

 consistence in front, finishes by attaching itself between the 

 two vomeres. 



In the anterior membranous partitions of the cranium is an 

 osseous branch, at first, crescent-formed, to surround the pos- 

 terior or external edge of the optic foramen, and then giving 

 out a point in front and one above, which extend themselves in 

 the membrane and assist to support it. This is the sole re- 

 presentative of the orbital and temporal wings. 



The vomeres form the middle of the under part of the palate, 

 going from the intermaxillary bone to the palatines, and hol- 

 lowed each of them in front into a small canal. 



All the anterior and lower part of each great osseous nostril 

 is occupied by a bone formed like a spoon, which seen from 

 above is concave behind, and convex in front, and which mani- 

 festly corresponds to the lower cornet of the nose. It proceeds 

 in all this part from the vomer to the maxillary, leaving under- 

 neath, in front, between the maxillary and the vomer, a hole 

 which penetrates into its convex part. 



A little more in front, on each side, is an incisive foramen 

 between the maxillary and intermaxillary bones. 



Besides its eight intermaxillary teeth, this monitor has usu- 

 ally eleven teeth in each maxillary bone, and as many on each 

 side of the lower jaw. The anterior are conical and pointed, 

 the hinder blunt. 



With the exception of some trivial differences of proportion, 

 such is the structure of all the monitors. The principal of 



