230 



CHELONIA. 



resembles the corresponding part of the larger humerus of 

 P. gigas, figured by Cope in the ' Eep. U.S. Geol. Surv. 

 Terrs/ vol. ii. pi. xii. fig. 2. The moderately deep emar- 

 gination of the postaxial border and the approximation 

 of the radial process to the head are clearly shown. 



Capron Collection. Purchased, 1879. 



49926 a. The imperfect proximal portion of a nearly similar right 

 humerus ; from the Chalk of Dorking, Sussex. The head 

 and mesial process are wanting. Cajjron Coll. 



Fig. 53. 



Protostega anglica. — Ventral aspect of the imperfect left humerus ; 

 from the Cambridge Greensand. \. Letters as in fig. 51. 



35316. The imperfect proximal portion of a similar right humerus ; 

 from the Cambridge Greensand. The head is entire, and 

 the sharp edge of the inferior border of the radial process 

 is shown. Purchased, 1859. 



35365. The proximal half of a considerably larger left humerus of 

 {Fig.) tho same type as the preceding ; from the Cambridge 

 Greensand. This specimen (fig. 53), which has been 

 somewhat waterworn, although most of the characteristic 

 features are shown, is the type, and is noticed by the 

 writer in the ' Quart. Journ. Geol. Soc' vol. xlv. p. 236. 



Purchased, 1859. 





