REPTILIxi. 



205 



ably be removed from the LcK^crtilia ; but this point cannot 

 in the meanwhile be definitely decided in the affirmative. 



Amongst other Triassic, or supposed Triassic, Lacertilians, 

 may be mentioned Saurosternon and Pristerodon, from strata 

 believed to be of Triassic age in Africa, and Centemodon from 

 deposits of the same age in North America. 



In the Jurassic period the remains of Lacertilians are not 

 very uncommon, but call for little special notice. Several 

 forms of little importance have been described from the 

 Middle Oolites. In the fresh-water strata of the Purbeck 

 series (Upper Oolites), occur the remains which have been 

 referred to the genera Nuthetes, Macellodon, Saurilhis, and 

 Echinodon. These are, perhaps, the first traces in the strati- 

 fied series of remains, the affinities of which to the typical 

 LacertidcB cannot be disputed. 



In the Cretaceous series occur the small Lizards which 

 constitute the genera Maj)liiosa%iTiis, Coniosaurus, and Doli- 

 chosaurus. Here also, and almost exclusively confined to 

 strata of this age, occur the singular Lacertilians which form 

 the group of the "Mosasauroids " {Mosasauridce). These re- 

 markable Eeptiles were of gigantic size, Mosasaurus prioiceps 



Fig. 556 — Skull of Mosascmrus Ca'/iqxri, much reduced. Maestrlclit Chalk. 



being believed to have attained the enormous length of not 

 less than seventy-five feet. Originally referred to the Ccta- 

 cea (Camper), and subsequently regarded as CrocodiKan, the 



