344 PETRIFACTIONS AND THEIR TEACHINGS. CHAP. III. 



British Palaeontology, attests in a striking manner the sagacity, 

 and consummate skill, and profound knowledge of the 

 Cuvierian philosophy, of our eminent countryman, the Rev. 

 W. D. Conybeare. 



In the first specimen, the cranium and jaws are somewhat 

 crushed; of the vertebral column, a great portion of the 

 cervical and caudal regions has the bones in connexion ; but 

 the dorsals are much dislocated, and the ribs displayed. The 

 anterior right, and the left hinder extremity, are almost entire : 

 the corresponding paddles are imperfect, and somewhat dis- 

 placed. The pectoral arch is not seen, but the " sterno-costal- 

 arcs" that protected the abdomen, are perceptible. Of the 

 pelvis, the principal bones remain ; the caudal vertebrae and 

 their hsemapophyses are beautifully shown. 



A good idea of the general form of the living Plesiosaurus 

 is conveyed by this fine specimen ; and the correctness of the 

 restoration of the entire skeleton given by Mr. Conybeare, 

 (PL XLIX. of the same vol.) has been established by subse- 

 quent discoveries, and especially by the perfect examples 

 which the researches of Mr. Hawkins have brought to light. 

 I subjoin a few remarks from the original Memoir, and some 

 additional details of the structure of these marine saurians. 



"The neck is fully equal in length to the body and tail 

 united ; and which, surpassing in the number of its vertebrae 

 that of the longest-necked birds, even the Swan, deviates from 

 the laws which were heretofore regarded as universal in quad- 

 rupedal animals and the cetacea. The whole vertebral column 

 numbers about 90 joints, viz. 35 cervical, 6 anterior dorsal, 

 21 dorsal and lumbar, 2 sacral, and 26 caudal. The propor- 

 tion of these parts will stand nearly thus ; taking the head as 

 1, the neck will be 5, the body 4, and the tail 3 : the whole 

 length being 13 times that of the head. 



" The general proportions of the Tortoise, its length of neck, 

 shortness of tail, and the small ness of its head, are in some 

 degree analogous to what we observe in the Plesiosaurus ; but 

 the structure of the head and teeth of the latter, and its want 

 of shell, entirely negative the idea of its being intimately 

 allied to the chelonians, and decidedly connect it with the 

 saurian order." 



The vertebrse are recognised by their nearly flat articular 

 facets, and the presence of two small vascular pits on the 



