64 * ENALIOSAURI. 



the back of the neck with a longitudinal band of 8 — 10 

 strongly keeled scales, placed in 4 or 5 cross rows of 2 each ; 

 the back with six rows of shields. 



? Ord. III. ENALIOSAURI. Conybeare. 



Vertebrae dorsi costaeque mobiles ; vertebrae colli plerumque 

 numerosse ; sternum breve ; claviculee breves latae ; os den- 

 tatum, dentibus in foveolis vel fissuris positis ; oculi magni 

 (nocturni) ; nares basales suborbitales : tympanum externum 

 nullum ; pedes pinniformes ; cauda brevis compressa. 



The vertebrae, ribs, sternum, and clavicles, are like those 

 of lizards, except that the articulating surfaces of the vertebrae 

 of the Enaliosauri are concave, like those of fishes. 



AH the animals of this order being found in the fossil state, 

 nothing is known of the appendages which protect their skin, 

 or of the fleshy parts of the body. I have placed the order 

 among the Cataphracta with doubt, as M. Cuvier, although 

 he boasts of the complete knowledge of the osteology of these 

 animals, does not mention the position of the bone, nor 

 have I been able to observe the position of this bone in any 

 of the skulls which I have seen, Cuvier has justly remarked 

 that if very perfect specimens of these animals had not been 

 found, there would be great reason to doubt their authenti- 

 city ; for the first genus presents the muzzle of a dolphin, 

 the teeth of a crocodile, the head and sternum of a lizard, the 

 legs of a whale (but four in number), and lastly, the vertebrae 

 of a fish. The second [Plesiosaurus] has the same cetaceous 

 feet and lizard head, with a long neck like the vertebrae of a 

 snake. — Cuv. Os. Fos. v. 445. 



We are almost entirely indebted to the industry and per- 

 severence of the Rev. Mr. Conybeare, for the knowledge of 

 these animals. They are only found fossil in the older for- 

 mations of Europe. 



Gen. I. ICHTHYOSAURUS, Koenig. 



Caput magnum ; coUum breve ; denies in sulco utrinque 

 insertae. 



