PLESIOSATJEID^. 



219 



35341. An imperfect (?) "pectoral" vertebra. Figured by Owen, 

 (Fig.) op. cit. pi. iii. figs. 5, 6. Purchased. 1859. 



36152. Four imperfect centra belonging either to the " pectoral" or 



lumbar region. Purchased, 1861. 



R. 483. A very similar specimen belonging to an adult individual. 

 Presented by Sir R. Owen, K.C.B., 1884. 



36153. The centrum of an anterior dorsal vertebra. Length 0,037 



(1-46 inches), height 0,051 (2-0 inches), width 0,068 

 (2*7 inches). This specimen resembles the earlier dorsal 

 figured by Owen, op. cit. pt. i. pi. xxi. fig. 1, as P.pachy- 

 omus. Purchased, 1861. 



36153 a. Two similar specimens, not improbably associated with 

 the preceding. Purchased, 1861. 



35284. The rolled centrum of an anterior dorsal vertebra. 



Purchased, 1859. 



35305. The centrum of a small later dorsal vertebra. The contour 

 of the terminal faces has become subcordiform. 



Purchased, 1859. 



36153 b. A larger imperfect centrum, probably belonging to the 

 later dorsal series of this species. Purchased, 1861. 



The following specimens indicate the existence of this or a closely 

 allied species at the period of the Lower Greensand ; their resem- 

 blance to the Upper Cretaceous specimens and the absence of 

 vertebrae of similar type in the Kimeridge Clay indicate that 

 these specimens were not derived from the latter deposit. No cha- 

 racters are shown by which these vertebrae can be distinguished 

 from those from the Cambridge Greensand. 



42090. Two imperfect anterior cervical vertebra) ; from the Neo- 

 comian bone-bed of Potton, Bedfordshire. 



Purchased, 1870. 



40453. Three imperfect anterior cervical vertebra) ; from Potton. 



Purchased, 1867. 



40453 a. The centrum of a " pectoral " vertebra ; from Potton. 



Purchased, 1 8(57. 



42032. The centrum of a " pectoral " vertebra ; from Potton. 



Purchased, 1870. 



