Structure of the Fossil Saurians. 341 



Art. II. On the Structure of the Fossil Saurians. (From the " Pa- 

 laeologica zur Geschichte der Erde und ihrer Geschbpfe ; von 

 Hermann von Meyer. Frankfort, 1832.) Translated by G. F. 

 Richardson, Esq., Curator of the Sussex Royal Institution, 

 and Mantellian Museum, Brighton. Communicated by Gideon 

 Mantell, Esq., LL.D. F.R.S. 



(Concluded from p. 293.) 



B. Saurians with Limbs similar to those of the large terrestrial Mammalia, 



1. Megalosau'rus. 

 Under this name Professor Buckland of Oxford has made 

 known the remains of one of the most gigantic of animals. In 

 all probability, its length must have been from 30 to 45 French 

 feet. The teeth are very like those of the Geosaurus ; flat, 

 pointed, bent backwards, and furnished with two finely ser- 

 rated edges, of which the foremost is somewhat stronger than 

 the other. The teeth appear to stand in tolerably well-closed 

 alveoli, and the replacing tooth breaks through the jaw and 

 the alveoli on the inner side. The teeth, indeed, are not 

 united to the jaw ; in which respect the animal bears a re- 

 semblance to the Monitor. Yet, notwithstanding this similarity 

 of the teeth with those of the Geosaurus, the structure of the 

 rest of the skeleton differs very considerably. Among the 

 bones yet found, some remind us of the Crocodile, others of 

 the Monitor, while others have not yet been sufficiently de- 

 termined. The beak appears to have been straight and elon- 

 gated. The width of the vertebrae, at present discovered, 

 exceeds their length by a third ; they are contracted in the 

 middle, as in Streptospondylus. Both surfaces are plane: 

 the spinous process is moderately high, and somewhat qua- 

 drangular, and the transverse processes are tolerably long. 

 The ribs have a head, and a tubercle similar to that of the 

 Crocodile. The metacarpal and metatarsal bones remind us, 

 at the first view, rather of the large terrestrial Mammalia (for 

 instance, the Hippopotamus) than of the Saurians. 



2. Igua'nodon Mantell. 

 Still more remarkable than the animal just mentioned, and 

 even more dissimilar to the existing Saurians, is the Iguanodon 

 described by Mantell. Its teeth bear marks of detrition, like 

 some of those of the herbivorous Mammalia. Cuvier thought 

 some of them similar to the incisors of the Rhinoceros. The 

 largest tooth is 20 times larger than the tooth of the living 

 Iguana. The teeth are variously formed, according to their 

 situation and their degree of use. In the young animal they are 



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