FOSSIL REPTILES. 291 



the lachrymal occupies much more space. The posterior 

 frontal is united to the parietal ; a wide suborbital, divided 

 into many pieces, is united to the anterior frontal, the prin- 

 cipal, and the posterior frontals. The pterygoidean bones 

 have each a range of small teeth near their internal edge, 

 almost midway of their length. There is a small foramen in 

 the middle of the parietal. 



In the stellio uromastix (Merrem.), of which there are two 

 species, the head is depressed and widened externally, so as 

 to produce a swelled appearance of the cheeks from the size 

 of the jugal bones. The frontal is very narrow; the nasal 

 bones small and short; the external nostrils and the orbits 

 very large ; the hinder branches of the parietal very long. 

 When this bone joins the frontal, it is emarginated by a wide 

 foramen, closed by a simple m-embrane. The anterior and 

 posterior frontals are very small ; the palatines broad and 

 short. There are no teeth in the intermaxillary bone, the 

 edge of which projects between the maxillary teeth. 



In the common Stelliones the frontal is shorter; orbits 

 and nostrils not so large. There are two teeth in the inter- 

 maxillary, and the second of the maxillary teeth is a sort of 

 canine. 



In the iguanas the muzzle is swelled and convex; the 

 frontal is flat ; the anterior frontal is broad upon the cheek, 

 and has a tubercle in front of the orbit. The posterior frontal 

 is divided into two parts. The internal nostrils are very long, 

 and the palatines very wide. 



The geckos differ much from the other lizards, by the 

 extreme smallness of the osseous parts of the jugal and tem- 

 poral, and the longitudinal division of the parietal into two 

 bones. The muzzle varies in elongation and depression, ac- 

 cording to the species. The principal frontal is broad, and 

 slightly concave. The orbit is large, round, and incomplete 

 on the side of the temple. A great part of the hinder edge of 

 the orbit is visible only by a ligament, in consequence of the 



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