PLESIOSAUMDJE. 245 



(2-67 inches), height 0,053 (2-1 inches), width 0,075 

 (2*95 inches). Its contour closely resembles that of the 

 cervicals of C. truncatus. 



Tesson Collection. Purchased, 1857. 



R. 256. An imperfect " pectoral " vertebra, which may belong to a 

 smaller individual of the same form as the preceding ; from 

 the Great Oolite (Lower Jurassic) of Oxfordshire. 



Egerton Collection. Purchased, 1882. 



44904. The greater portion of a mandible which is not improbably 

 specifically identical with the preceding ; from the Great 

 Oolite of Essendine, near Stamford, Lincolnshire. The 

 symphysis is entire and of the usual shortness, but the 

 crowns of the teeth are broken off. 



Presented by Sir R. Owen, K.C.B., 1874. 



Cimoliosaurus (?) sp. 



(Cf. Plesiosaurus erraticus, Phillips 7 .) 

 The undermentioned specimens indicate a much smaller form than 

 the preceding, for which, if it proves distinct from all the Liassic 

 species of Plesiosaurus, the above specific name may be adopted. 

 Hah. Europe (England). 



R. 272. An imperfect anterior or middle cervical vertebra; from 

 the Stonesfield Slate (Lower Jurassic) of Stonesfield, 

 Oxfordshire. Egerton Collection. Purchased, 1882. 



47995. A nearly entire "pectoral" vertebra ; from Stonesfield. The 

 anchylosis of the arch to the centrum indicates maturity. 

 Presented by the Hon. II. Mar sham, 1877. 



31818. A right humerus, agreeing in relative size with the pre- 

 ceding; from Stonesfield. Purchased, 1859. 



Serial Position Uncertain. 



Cimoliosaurus hoodi (Owen J ). 

 Syn. Plesiosaurus hoodi, Owen :i . 



Described on the evidence of a single cervical vertebra. 

 Jfab. Now Zealand. 



1 Geology of Oxford, p. 1*3 (1871).— No description. 

 a Geol. Mag. dec. 1, vol. vii. p. o'6 (1870j. — Plcsiosauni*. 

 3 Loc. cit. 



