MEGALOSAURUS. 269 



M. Hermann V. Meyer has proposed the name of Protorosaurus 

 Speneri for the Thuringian Monitor, but he has not added any new 

 fact relative to its organization. 



This name I shall retain,, because the species in question actually 

 differs from the existing Monitors and other Lacertians by the same 

 character which distinguishes the Thecodontosaurus , viz : the implanta- 

 tion of the teeth in distinct sockets. Of these sockets, the dislocated 

 ramus of the lower jaw in Spener's specimen exhibits fourteen, 

 which are of a square shape with the angles rounded off, close set and 

 sub-equal. The teeth, of which eighteen may be counted in the 

 upper jaw, are relatively longer, more slender, and more cylindrical 

 than in the Thecodon ; they are more or less broken ; the most perfect 

 of them measure three lines in length, and two-thirds of a line across the 

 base ; they are of a jet-black colour, and, being imbedded in a dark 

 matrix, have not enabled me to determine whether the Protorosaurus, 

 like the equally ancient reptiles of the Bristol conglomerate, had the 

 teeth armed with serrated ridges(l). 



MEGALOSAURUS. 



115. The compressed varanian form of tooth, with trenchant and 

 finely dentated margins, which characterized the ancient Palseosaur 

 and Cladeiodon, is continued in the comparatively more recent and 

 gigantic species of terrestrial lizard, of which the remains were dis- 

 covered by Dr. Buckland in the oolite of Stonesfield. The characters 

 and peculiarities of the jaws and teeth have been so accurately and 

 graphically described by their discoverer, that an apology would be 

 due rather for suppressing, than for here reproducing them. 



" From these," says Dr. Buckland, " we learn that the animal 

 was a reptile, closely allied to some of our modern lizards, and 

 viewing the teeth as instruments for providing food to a carnivorous 

 creature of enormous magnitude, they appear to have been admirably 



celui de Swedenborg parmi les guenons ou les sapajous ; mais on les rangera tous parmi les 

 monitors ou tupinambis. Ossem. fossiles, 4to. vol. v, p. 306. 



(1) Besides the thecodont type of dentition, the Protorosaurus differs from all recent Saurians 

 and resembles the Pterodactyle in the great relative size of the cervical vertebrje, and the ossified 

 tendons of the muscles of that region of the spine ; it differs from all reptiles, except the extinct 

 Racheosaurus in the bifurcate superior spines of the caudal vertebrae. 



