ON BRITISH FOSSIL REPTILES. 103 



tebrse of unusual construction, by the height and breadth and outward sculp- 

 turing of the neural arch of the dorsal vertebrae, by the twofold articulation 

 of the ribs to the vertebrae, viz. at the anterior part of the spine by a head 

 and tubercle, and along the rest of the trunk by a tubercle attached to the 

 transverse process only ; by broad and sometimes complicated coracoids and 

 long and slender clavicles, whereby Crocodilian characters of the vertebral 

 column are combined with a Lacertian type of the pectoral arch ; the dental 

 organs also exhibit the same transitional or annectent characters in a greater 

 or less degree. The bones of the extremities are of large proportional size, 

 for Saurians ; they are provided with large medullary cavities, and with well 

 developed and unusual processes, and are terminated by metacarpal, metatarsal 

 and phalangeal bones, which, with the exception of the ungual phalanges, 

 more or less resemble those of the heavy pachydermal Mammals, and attest, 

 with the hollow long -bones, the terrestrial habits of the species. 



The combination of such characters, some, as the sacral ones, altogether 

 peculiar among Reptiles, others borrowed, as it were, from groups now distinct 

 from each other, and all manifested by creatures far surpassing in size the 

 largest of existing reptiles, will, it is presumed, be deemed sufficient ground 

 for establishing a distinct tribe or sub-order of Saurian Reptiles, for which I 

 would propose the name o{ Dinosauria*. 



Of this tribe the principal and best established genera are the Megalosau- 

 rus, the Hi/lcBosmirus, and the Iguanodon ; the gigantic Crocodile-lizards of 

 the dry land, the peculiarities of the osteological structure of which distin- 

 guish them as clearly from the modern terrestrial and amphibious Sauria, as 

 the opposite modifications for an aquatic life characterize the extinct Ena- 

 liosauria, or Marine Lizards. 



Megalosaurus. 



Of the gigantic Lacertians in question, the most remarkable are the Mega- 

 losaurus, Iguanodon, and HylcBosaurus, the worthy fruits of the laborious re- 

 searches of Prof. Buckland and Dr. Mantell. With respect to the Megalo- 

 saurus, the great carnivorous terrestrial Lizard of the Wealden and Oolitic 

 period, the lucid descriptions of its discoverer in his original Memoir and the 

 'Bridgewater Treatise,' and the judicious remarks of Cuvier on its natural 

 affinities, leave little to be added, save the observations on the sacrum, to the 

 present brief record of the strata and localities in which the remains of the 

 Megalosaurus have been found. 



The most complete collection of the bones of this genus has been derived 

 from the oolite of Stonesfield, where the original specimens were first dis- 

 covered. Dr. Buckland now possesses in his valuable collection portions of a 

 lower jaw, the principal fragment containing a tooth fully developed, and the 

 germs of several others ; detached dorsal, caudal, and a series of five sacral 

 vertebrae, ribs, two coracoid bones, a clavicle, humerus, radius, an ilium, an 

 ischium, a femur, fibula, metacarpal and metatarsal bones. 



These parts have not been discovered so associated together as to prove 

 them to belong to the same animal ; but the peculiar characters of some of 

 the bones, which distinguish them from the other oviparous reptiles of the 

 same strata, and the agreement in texture and proportionate size of the others, 

 render their reference to the Megalosaurus highly probable. 



* Gr. (Jeivos, fearfully great ; cravpos, a lizard. In the tabular arrangement of extinct 

 Saurians founded by M. Herni. v. Meyer on the development of their organs of motion, the 

 Megalosaurus and Iguanodon are grouped together in Section B, with the following cha- 

 racter: — Saurians with locomotive extremities like those of the bulky tenestrial Mammals: 

 •' (Saiiricr mit Ghedmasseu iihnlich denen der schweren Landsaiigethiere)." — Palseologica, 

 p. 201. No other grounds arc assigned for their separation from other Sauriaus. 



