PLESI0SAURID.2E. 209 



Cimoliosaurus oxoniensis (Phillips 1 ). 

 Syn. Plesiosaiwus oxoniensis, Phillips 2 . 



Typically of very small size, by which character alone, so far as 

 is at present known, it is distinguished from the preceding form. 

 Judging from the similarity in the vertebrae, the limb-bones were 

 probably like those of 0. eurymerus. The pectoral girdle figured 

 under the name of the present species on p. 310 of Phillips's ' Geo- 

 logy of Oxford ' in a reversed position, and regarded as the pelvis, 

 was not associated with the type vertebrae, but was obtained from 

 the Oxford Clay of Summertown, Oxfordshire, in association with 

 the pectoral limb figured on p. 312 of the same. In the latter 

 figure the ulna (fibula of Phillips) is relatively too long, and the 

 arrangement of the bones on the postaxial border is incorrect ; the 

 whole contour of the specimen is, however, that of C. plicatus, to 

 which it thus appears that both the pectoral girdle and limb should 

 be referred. Apparently on the evidence of this girdle the present 

 species was referred by Seeley 3 to a subgenus of Muramosaurus ; the 

 restoration given by Phillips is, however, incorrect, since the speci- 

 mens themselves distinctly show the remains of a bar connecting 

 the scapulae with the coracoids in the middle line. Whether the pre- 

 ceding form is more than a large race of the present species has 

 to be proved. 



Hob. Europe (England and [?] France). 



R. 1285. Casts of three imperfect vertebrae belonging to the cervical, 

 dorsal, and caudal regions. The originals are the types ; 

 and were obtained from the Oxford Clay (Middle Jurassic) 

 of Long-Marston, Oxfordshire, and are preserved in the 

 Museum at Oxford. The cervical is the last of the series 

 of six figured on p. 308 of Phillips's ' Geology of Oxford/ 

 In tho cervical the dimensions of the centrum are : — length 

 0,028 (1-1 inches), height 0,033 (1*3 inches), and width 

 0,041 (1*6 inches) ; the corresponding dimensions of the 

 dorsal being: — length 0,043 (1*7 inches), height 0,049 

 (1-94 inches), width 0,055 (2-18 inches). ~ Phillips 

 regarded the cervicals as being close to the head, but this 

 appears to be incorrect. The caudal is one of the speci- 

 mens figured on p. 310 of Phillips's work. 



Made in the Museum, 1888. 



1 Geology of Oxford, p. 307 (1871).— PZesiosaurus. 



2 Loc. cit. 



3 Quart. Journ. Geol. Soc. vol. xxx. p. 448. 



PART n. P 



