EEPTILIA. 



61 



ter is generally found lying on the side ; the former, extended on its back. The 

 P. dolichodeirus is characterized by its extremely long neck and very small head. 

 The proportion of the parts is nearly thus : taking the head as 1, the neck will be 

 5, the body 4, and the tail 3 ; the whole length being thirteen times that of the 

 head. The four paddles are equal in size. This specimen from the British Mu- 

 seum was discovered in the Lias at Glastonbury, England. 



Size, 6 ft. x 2 ft. 9 in. Price, $18.00. 



No. 226. Plesiosaurus dolichodeirus, Conyb. 



Lower Jaw. From the Lias at Glastonbury, England, and now in the Mu- 

 seum of the Garden of Plants. Price, $1.90. 



No. 227. Plesiosaurus macrocephalus, Conyb. 



<<zr 



Skeleton on slab. This species is distinguished by the relatively larger 

 size of the head and thicker neck. The neck is three times the length of the 

 head ; and the posterior paddles are longer than the anterior pair. In this very 

 perfect specimen, belonging to the Earl of Enniskillen, Ireland, the vertebral column 

 is thrown into an arched position : the cervicals and dorsals form a continuous series; 

 the tail is imperfect. Three paddles are exposed, and the upper part of the 

 cranium with the orbits and the jaws and teeth are clearly defined. The original 

 was discovered in the Lias of Lyme-Regis, England, by Miss Mary Anning, and 

 described by Dr. Buckland. Size, 2 ft. 9 in. x 2 ft. 6 in. Price, $12.00. 



