196 MAEIKE EEPTILES OF THE OXFORD CLAY. 



Coracoid : width of the united bones at narrowest .... 33'0 

 width between the outer ends of the postero-Iateral 



processes 57'1 



Pelvis : greatest length 46'8 



width between the antero-external angles of the pubes. ()6'6 



Ilium : length 20-0 



width of upper end 6-2 



„ lower end 8'0 



Pubis : gi-eatest length 25-8 



„ width (from antero-external angle to sym- 



physial border) 34'2 



width of acetabular surface (approx.) 8-7 



depth of acetabular surface 5'9 



Ischium: gi-eatest length of median expansion 21-9 



width from acetabular surface to symphysis . . . 22-3 



width of articular head 10'7 



„ necli 6-7 



antero-posterior diameter of obturator foramen . 10'2 



E. 2417 (Leeds Coll. 36). A nearly complete skeleton of a very young individual. The parts 

 preserved are : — skull (imperfect and much broken), the occipital portion and the 

 basis cranii figured PI. IX. figs. 4, 4 a, 5 ; mandible (PI. IX. fig. 6) which carried 

 20-22 teeth on each side, atlas and axis (text-fig. 78, A, E), 30-31 other cervical 

 vertebrse, 2-3 pectorals, 21-22 dorsals, 3—4 sacrals, and about 21 caudals ; neural arches, 

 cervical, dorsal, and caudal ribs, ventral ribs, chevrons ; pectoral girdle and fore 

 paddles (imperfect) (text-fig. 90, A), pelvis (text-fig. 92), and hind paddles (imperfect). 

 This specimen was described and figured in the Geol. Mag. [4] vol. ii. p. 241, pi. ix. 

 The ossification of the vertebral column is imperfect, the elements making up the 

 atlas-axis complex being all free from one another, the neural arches nowhere fused 

 with the centra, and all the cervical and caudal ribs free ; the cartilage-covered surfaces 

 for union with the arches and cervical ribs are continuous with one another. The 

 ossification of the posterior caudal vertebrse seems even less advanced than it is further 

 forwards in the column. In the shoulder-girdle the ventral ramus of the scapula is 

 little developed, and probably did not extend at all beneath the clavicle ; in the fore 

 paddles there is little indication of the great distal expansion of the humerus character- 

 istic of the adult, but the radius is already large and generally similar in form to that 

 of the adult. 



The dimensions (in centimetres) of this specimen are : — 



Total length of the skeleton as mounted . . (about 6 feet) 1 84-0 

 SkuII (PL IX. figs. 4, 4 a, 5): 



length from occipital condyle to tip of snout .... 19-3 



,, of basioccipital 3-0 



width of basioccipital at pterygoid processes .... 3-0 



transverse diameter of occipital condyle 1-9 



Mandible: length • (approx.) 23-0 



,, of syraphysis (approx.) 2-2 



