176 BRITISH FOSSIL REPTILES. 



and their excavations indicate the usual mode of succession and displacement : a few 

 alternate teeth have been shed. 



The mode of attachment more resembles that which characterises the teeth in 

 Lacerta proper and other " coelodont" genera of the Lacertian tribe ; but in the number, 

 proportions, and general shape of the teeth, the present species more resembles some 

 of the Iguanian tribe. The anterior coronal groove is continued to the anterior 

 margin of the crown, which it slightly indents in the larger teeth ; but this is the only 

 approach to that complex structure which characterises the teeth of the typical 

 Iguanidce. PI. 2, fig. 19 a is a magnified view of the crown of one of the anterior 

 teeth ; and fig. 1 9 a of one of the posterior teeth. 



There is no existing species of the Iguanian or other herbivorous family, nor of any 

 of the ' pleurodont' Saurians, with which the present chalk-fossil is identical ; nor can 

 I refer it to any of the established genera of LacertUia. The absence of the cranium 

 and bones of the extremities, does not allow of any closer comparison with the Monitors, 

 Iguanas, or Scinks ; but the characters of the teeth justify the consideration of the 

 fossil as the type of a hitherto undescribed genus and species, which I therefore 

 propose to call Coniosaums crassidens, or the thick-toothed Lizard of the Chalk 

 formation. 



The specimens represented in figs. 18, 19, and 20, are from the Clayton chalk-pit 

 near Brighton : a smaller portion of a lower jaw and a few teeth have been obtained 

 bv Mr. Dixon from the Washington chalk-pit near Worthing : and vertebrae have been 

 found by Mr. Catt in the upper chalk near Palmer, during the cutting of the railroad 

 from Brighton to Lewes. These are the only specimens of the genus and species that 

 have jeX been discovered. 



Genus, Dolichosaurus,* Owen. 

 Dixon's ' Geology of Fossils of the Tertiary and Cretaceous Formations of Susse.x,' 4to, p. 388. 



Species, Dolichosaurus longicollis. (Plate 8, figs. 1 and 2.) 



My esteemed friend the late Frederic Dixon, Esq., F.G.S., in the course of his 

 indefatigable inquiries respecting the fossils of the cretaceous period, obtained such 

 information relative to the unique specimen of the mutilated head and anterior thirty 

 six vertebrae of the fossil Lizard from the lower chalk of Kent, in the admirable 

 collection of Mrs. Smith of Tunbridge Wells, figured in PI. 8, fig. 1, as left no doubt 

 in his mind that it formed part of the same skeleton with the chain of posterior 

 abdominal and sacral vertebrae in the collection of Sir P. de M. Grey Egerton, Bart., 

 M.P., F.G.S., and which is figured in the ' Geological Transactions/ 2d Series, vol. vi, 

 pi. 39 ; and in the present work at PI. 9, fig. 4. 



* AoXij^os, long, aavpos, lizard. 



