PLESIOSAURIDiE. 161 



dimensions nearly or quite as large as those of T. cramptoni. Teeth 

 long and slender, with slight curvature of the crown, and the 

 ridges on the concave surface wide apart and stopping short at the 

 summit, the carinas being strongly developed. 



The transverse diameter of one of the typical dorsal vertebras is 

 0,114 (4*5 inches); this is smaller than in the dorsals of the type of 

 T. cramptoni, but the fragments of jaws figured by Meyer indicate 

 individuals apparently quite as large as the latter, the same being 

 indicated by some of the undermentioned teeth. The types are 

 figured in the ' Pala?ontographica,' vol. vi. pis. iv., v., where the sub- 

 cylindrical terminal faces and the two costal facets of the cervical 

 vertebras are well shown. 



Hah. Europe ("Wurtemberg and Prance). 



32608. The crowns of four teeth ; from the Great Oolite (Lower 

 Jurassic) of Caen, Calvados, France. A similar specimen 

 is figured by Deslongchamps in the ' Mem. Soc. Linn. 

 Xormandie,' vol. vi. pi. vi. fig. 8 (1836), where it is re- 

 ferred to Mec/alosaurus {Poelcilopleuron) hucldandi. The 

 fragment of the type tooth figured by Meyer in the ' Pahe- 

 ontographica,' vol. vi. pi. iv. fig. 7, seems to agree exactly 

 with these specimens. Except for their larger size, these 

 teeth are scarcely distinguishable from those of Peloneustes 

 philarchus, and appear identical with those of T. cramp- 

 toni. They are noticed by the writer in the ' Quart. Journ. 

 Geol. Soc' vol. xlv. p. 50. 



Tesson Collection. Purchased, 1857. 



27483. A similar tooth ; from Caen. 



Hastings Collection. Purchased, 1855. 



Thaumatosaurus cramptoni (Carte & Baily ] ). 



Syn. Plesiosaurus cramptoni, Carte & Baily 2 . 

 Rhomaleosaurus cramptoni, Seeley 3 . 



The type of Rhomaleosaurus. Of gigantic size; the length of tho 

 type skeleton as it lies being 22 feet 4 inches. From 25 to 30 teeth, 

 which are apparently similar to those of T. oolithicus. About 1)2 

 vertebras (some of the caudals being perhaps wanting), which aro 

 reckoned as 27 cervical, 30 " pectoral " and dorsal, and 34 caudals. 

 Humerus shorter than femur. Three bones in each row of tho 

 carpus and tarsus. Pectoral and pelvic girdles unknown. Cervical 



1 Journ. R. Dublin Hoc. vol. iv. p. 1G1 (1863). — Plesioscmrus. 2 Log. cit. 



3 Quart. Jouru. Geol. Soc. vol. xxx. p. 418 (1874). 

 PART II. M 



