MUE^NOSAUEUS DUEOBEIVENSIS. 127 



The dimensions (in centimetres) o£ this shoulder-girdle are : — • 



Total length of the whole on middle line 7o'0 



Scapula: greatest length 33'C) 



length from anterior angle to posterior end of ventral 



ramus 24-6 



length on a straight line from posterior angle of 



ventral ramus to tip of dorsal ramus 26-6 



approx. width of glenoid surface from before baek- 



\\'arJs 5'2 



approx. width of glenoid surface from above down- 

 wards 46 



Coracoids : greatest length 48'9 



width of united bones at hinder angle of glenoid 



cavity 40-8 



width of united bones at narrowest 2S'2 



,, „ betweentheposteriorexternal 



angles (approx.) 4-9 



anterb-posterior diameter of coraco-scapular foramen. 13'2 



transverse diameter of ditto (approx.) 9-4 



Interclavicle (PL VI. fig. 6) : length (approx.) 11-9 



width (approx.) 14-2 



E, 244:3a. Left femur probably of this species, figured in Phillips, 'Geology of Oxford, etc./ 

 p. 317, text-fig. cxxi., as belonging to Pliosaurus cfi-amlis. 



Muraenosaurus durobrivensis, Lydekker, sp. 



[Plate V. ; text-figs. 43, 45, 49-57, 60, 65, 67.] 



1889. Cimoliosaurus durohrwensis, Lydekker, Catal. Foss. Rept. Brit. Mus. pt. ii. p. viii. 

 1895, Murcenosaurus plicatus, Andrews, Ann. Mag. Nat. Hist. [6] vol. xvi. p. 429 (pars). 



Ti/j)e Siyecimen. — An imperfect skeleton, including thirty cervical vertebree, fifteen 

 dorsals, and some caudals, wanting ribs and arches ; shoulder-girdle wanting the 

 clavicular arch ; imperfect fore paddle ; pelvis including both ilia and ischia and the 

 pubis ; imperfect hind paddles (R. 2428, Leeds Coll. 28). The pectoral and pelvic 

 girdles have been described and figured in Ann, Mag. Nat. Hist. [6] vol. xvi. (1.895) 

 p. 429 (see also PL V, ; text-figs. 43, 45, 49-57, 60, 65, 67). 



This species was established by Mr. Lydekker for the reception of an Oxford Clay 

 Plesiosaur which, while closely resembling his Cimoliosaurus plicatus, difi'tTS in wanting 

 the median bony bar uniting the coracoids and scapulae, and in possessing cervical 

 vertebrse with relatively shorter centra, especially in the posterior portion of the neck. 

 The absence of the median bony bar in the shoulder-girdle is probably merely an 

 age-character, but the shortness of the cervical vertebrte is a well-defined peculiarity 

 and is accompanied by others which distinguish this species from the other members of 



