PLESIOSAURID^E. 273 



a large part of the cervical and dorsal regions of the 

 vertebral column, one entire and one broken propodial 

 bone, and some other fragments of the limbs. In the 

 skull the size of the supratemporal fossa accords precisely 

 with that of the type ; but no other comparisons can be 

 made. The division between the cervical and dorsal 

 regions of the vertebral column cannot be determined ; 

 but apparently at least 30 cervicals may be counted. 

 These cervicals have comparatively short centra, in which 

 the terminal faces are deeply cupped at the centre, with 

 bevelled edges, the haemal surface having a prominent 

 ridge flanked by a deep pit on either side ; the costal 

 facets are very low down on the centrum and may be 

 undivided ; and the neural spines are very short and 

 broad, with the characteristic terminal contour. The 

 dimensions of the centrum of the 11th vertebra remaining in 

 the series are : — length 0,034 (1'35 inches), height 0,040 

 (1*56 inches), width 0,046 (1*8 inches). In all these 

 respects these vertebrae agree with those of the type, and 

 since they are quite different from the corresponding 

 vertebrae of P. macrccephalus and P. conybeari, there can 

 be little doubt that the specimen belongs to the present 

 species. The early dorsals have the transversely expanded 

 terminal faces of the exposed dorsal of the type, but their 

 absolute size has been reduced by the exposure to which 

 the specimen has been subjected. The vertebrae accord 

 very closely with the description of those of P. longirostris 

 (coelospondylus). No history. 



39849. A slightly imperfect middle cervical vertebra ; from Lyme- 

 (Fig.) Regis. This specimen (woodcut, fig. 81) closely resembles 

 the 12th or 13th of those in apposition in the preceding 

 specimen ; and is quite indistinguishable from the 15th of 

 the type skeleton, of which a correct lateral view is given 

 by Owen, op.cit. pi. x. fig. 1. The peculiar contour and 

 extreme shortness of the neural spine is well shown, and 

 the costal facets appear to be single. On the haemal 

 aspect the pits flanking the median ridge are very 

 distinct. The dimensions of the centrum are: — length 

 0,043 (1-G9 inches), height 0,044 (1*72 inches), width 

 0,050 (1/96 inches), the total height of the specimen 

 being 0,104 (4*1 inches). Purchased, L866. 



28318. An associated series of sixteen somewhat imperfect ver- 



PART II. I 



