FOSSIL REPTILES OF DORSET. 23 



Most of the bones retain their relative position, and the 

 excellent preservation of one of its fore-paddles was probably 

 owing to the casual preservation of the original integument before 

 sinking into the Liassic mud. The skull is much larger than Pies, 

 dolicliodeirus, being one foot eleven inches long, and nine inches broad, 

 seven inches and a-half across the skull behind the orbits and only 

 two inches across the narrowest part of the snout. It approaches 

 Teleosaurus in the lengthening out and attenuation of the jaw. 

 PLESIOSAURUS RUGOSUS, Owen. 



The wrinkled exterior margin of the vertebrae of this species, 

 and the surfaces of the femur and humerus, suggested to Sir R. 

 Owen the specific name rugosus. The head has never yet been 

 found, but from the small size of the surface of the upper cervical 

 vertebrae, which were about thirty-four in number, as well as from 

 the length of the neck, it is probable the head was small, as in 

 Pies, dolichodeirus. Parallel with the tibia and fibula is an ossicle, 

 regarded by K. Owen as probably the homologue of the patella, 

 which is found also in Pliosaurus. 



PLESIOSAURUS HAWKINSII, Owen. 



The head of this species is somewhat larger than that of Pies, 

 dolichodeirus, the neck equals three lengths of the head, and the 

 neck and head together equal the trunk. The number of cervical 

 vertebrae is six less than in the species just named, but shorter in 

 the neck by six cervical vertebrae. The teeth have the usual 

 genuine type, long, slender, and slightly recurved with fine 

 longitudinal striae ; the upper jaw is armed with about forty teeth 

 on each side, the lower jaw with about thirty-four ; the ischium 

 and pubis, which is large and square-shaped, together form the 

 foramen ovale, as well as the cavity to receive the femur ; there 

 are six carpal bones. From the Ostrea beds of the Lower Lias, 

 Lyme Regis. 



PLESIOSAURUS MACROCEPHALUS, Owen. 



The head of the species is larger than that of Pies. Haivkinsii ; the 

 vertebrae of the neck are stouter, and they have costal processes for 

 the attachment of muscles to facilitate the movement of its large 



