254 SAUKOPTEKYGIA. 



shown. The dimensions of the larger centrum are : — length 

 0,064 (2-5 inches), height 0,042 (1-65 inches), width 

 0,057 (2-24 inches). Presented by E. Charlesworth, Esq. 



40118. The imperfect centrum of a later cervical vertebra ; probably 

 from Whitby. The double costal facets are very beautifully 

 shown. The dimensions of the centrum are : — length 0,069 

 (2-7 inches), height 0,052 (2-05 inches), width 0,065 

 (2*75 inches). Purchased. 



32717. Five imperfect associated late cervical vertebrae ; from the 

 (F'uj.) Upper Lias of Curcy (Calvados), Prance. The first of the 

 series, which is figured with the spine restored in fig. 78, 

 although slightly larger, agrees very closely with the pre- 

 ceding specimen ; the dimensions of the centrum being, 

 length 0,069 (2*74 inches), height (posterior face) 0-056 

 (2-2 inches), width 0,074 (2-9 inches). The double costal 

 facets are clearly shown. 



Tesson Collection. Purchased, 1857. 



R. 1366. Two middle caudal vertebrae united by matrix, and wanting 

 the greater portion of the neural spines ; probably from 

 Whitby. The length of the centrum of the hinder of the 

 two is 0,047 (1-85 inches), and its width 0,054 (2-14 

 inches). These specimens accord closely with the middle 

 caudals of the type, and are relatively much larger than 

 those of any other species of the genus. The anterior one 

 has chevron-facets on the posterior border only, the hinder 

 on both borders. No history. 



R. 1367. Two very similar specimens ; from Whitby. Each 

 centrum has chevron-facets on both borders. No history. 



Plesiosauras, sp. 

 (Cf. Plesiosaurus deivalquii, Van Beneden \) 

 Imperfectly known. Smaller than the preceding ; cervical 

 vertebrae relatively shorter, with the terminal faces of the centra 

 more cupped, the haemal surface less flattened, with a distinct carina, 

 the costal facets less narrow, and the neural spines probably shorter. 

 The cervical vertebrae from the Lower Lias of Luxemburg, described 

 and figured by Van Beneden in the ' Mem. Ac. E. Belg.' vol. sliii. 

 art. 12, p. 41, pi. iv. (1880), under the name of P. dewalquii, 



1 Bull. Ac. E. Belg. ser. 2, vol. xxi. p. 15 (1871). 



