14 FOSSIL REPTILIA OF THE 



going vertebras ; in other respects the characters closely accord with those of the 

 posterior cervical centrum (figs. 5 and 6), and I regard the present as indicating 

 a mere variety in the proportions of the centrum, which is also less than it 

 appears in the plate, on account of the abrasion of the circumference of one of 

 the terminal articular surfaces. 



The dimensions of the restored centrum are: 



In. lines. 



Length 13 



Breadth of posterior surface ........ 1 8 



Height ..16 



The dorsal centrum (figs. 9, 10, 11) exhibits the characters already specified 

 in the comparison of it with the type- vertebra of Dr. Campiche's species ; the 

 chief or sole difference is the more circumscribed and smaller circumference of 

 the central mamilla of the terminal articular surface ; the neurapophysial pits 

 have undergone the change of form and proportions which brings them to the 

 same pattern as in the dorsal vertebrae figured in the ' Paleontologie Suisse,' 

 loc. cit. 



In the locality whence the specimens (figs. 1 — 6, 9 — 11, Tab. VI) were 

 exhumed, some portions of limb-bones were obtained of a Plesiosaurus of cor- 

 responding size, of which I select for figuring a left femur (fig. 12) and the lower 

 two thirds of a left humerus (fig. 13). The outline of a section through the broadest 

 part of the distal and of the humerus is given to the left of fig. 13, to exemplify the 

 difference in the proportions of this bone from the humerus of the Plesiosaurus 

 pachyomus from deposits of the same age. The outline connected by dots with 

 fig. 12 represents a section of the proximal end of that femur. I think it 

 most probable that both these bones appertain to the Plesiosaurus neocomiensis 

 of Campiche. 



Plesiosaurus latispinus, Owen. Cervical vertebrae, Tab. VII ; cervical and dorsal 



vertebrae, Tab. VIII; ilium and coracoid, 

 Tab. IX. 



This species was founded on the characters of the two cervical vertebrae figured 

 in Tabs. VII and VIII. They form part of a scattered series of about a dozen 

 vertebrae, with ribs, scapulae, portions of the coracoid bones (Tab. IX, fig. 2), an 

 ilium (Tab. IX, fig. 1), and a few other parts of the skeleton, included in a rock of 

 the " Shanklin-sand" or Lower Green-sand series, from the so-called " Iguanodon 

 Quarry," at Maidstone, Kent, where they were observed and partially wrought out 



