ON BRITISH FOSSIL REPTILES. 145 



scribed. From tlie correspondence in the general structure, smootli external 

 surface, and mode of attachment of tlie teeth between the Maestriclit Mosa- 

 saur and the English Leiodon, it may be concluded that the latter reptile had 

 the same affinity to the Lacertian type, which the Mosasaur so strikingly 

 manifests in the presence of pterygoid teeth. 



Genus Kaphiosaurus. 



Under this name I propose to notice a small and hitherto undescribed genus 

 of Lacertians, from tlie chalk I'ormations near Cambridge, indicated by a por- 

 tion of the lower jaw, containing twenty-two close-set, awl-shaped teeth an- 

 chylosed by their bases to an outer alveolar parapet of bone, and thus corre- 

 sponding with the pleurodout type of dentition among the Lizards. 



To the same genus may belong a beautiful specimen in the museum of Sir 

 Philip Egerton, consisting of a series of twenty dorsal, two lumbar, two 

 sacral, and a few of the caudal vertebrae, with the pelvic bones, from the chalk 

 near Maidstone, which correspond with the jaw of the Raphiosaiirus in size. 

 The vertebral characters are essentially those of the modern Lacertians ; but 

 the absence of extremities and teeth prevents the generic affinities being ac- 

 curately determined. 



It is interesting to find this second- instajiee of the ' procoelian ' type of 

 vertebrae — or those with the anterior cup and posterior ball — in the chalk 

 formations, below which I have not met with any instance of a Reptile agree- 

 ing with the existing species in this structure. 



Pleurodont Eocene Lizard. — Among the fossils obtained by Mr. Col- 

 chester from the Eocene sand, underlying the Red Crag at Kyson, or King- 

 ston, in Suffolk, the existence of a lizard, about the size of the Iguana, is in- 

 dicated by a part of a lower jaw, armed with close-set, slender, subcylindri- 

 cal, antero-posteriorly compressed teeth, attached to shallow alveoli, and with 

 their bases protected by an external jjarapet of bone. The fragment of jaw 

 is traversed by a longitudinal groove on the inside, and perforated, as in most 

 modern lizards, by immerous vascular foramina along the outside. The teeth 

 are hollow at their Ijase. 



Scincoid Oolite Lizard. — A small Lacertian is indicated by remains dis- 

 covered in the celebrated oolite at Stonesiield. The most intelligible of these 

 is a femur, ten lines in lengtli, having a hemispherical head supported on 

 a short subcompressed neck, on each side of the base of which there is a 

 strong conical trochanterian process : the middle of the shaft is cylindrical, 

 and soon expands to form a broad distal extremity. This shape of the bone 

 proves it not to be the young of any of the great Saui'ians hitherto discovered 

 at Stonesfield (the expansion of the distal end removes it from the Ciielonian 

 reptiles), but indicates its affinity to the Scincoidian lizards, the largest forms 

 of which, it may be remarked, now exist in Australia, where they are asso- 

 ciated with Araucaria: and cycadeous plants, with living Terebratulce, and Tri- 

 gonicE, and with the peculiar marsupial quadrupeds ; the remains of all which 

 forms of organized beings characterize the same stratum and locality as that 

 in which the present extinct Lacertian was found. 



No vertebras of tlie procoelian type have hitherto Iieen discovered in the 

 oolite, and it is most probable that those of the small Lacertian here indica- 

 ted, agree with those of most other extinct Saurians of the secondary forma- 

 tions in having both articular extremities subconcave. 



Genus Riiynchosaurus. 



The biconcave structure unquestionably characterizes the vertebra? of the 

 small Lacertian from the new red sandstone quarries near Shrewsbury, on 

 which the M'ell-mt\rkeU and distinct genus Rhynchosaurus is founded. 



1841, I, 



