ON THE PHYLOGENY OF THE CARAPACE, ETC. 795 
CBR the pelvis of the Protostegide and that of the Leatherback 
g. 2). 
3. There is only one central in the carpus.’ The different arrange- 
Fig. 2. A, Pelvis of Dermochelys, not yet fully adult, about } nat. size (after Volker 
1913, pl. 33, fig. 19), and B, Pelvis of Archelon, diagrammatic, about ys nat. size 
with the probable extent of cartilage in a young individual for comparison with 
fig. 2 A (based on figure of Wieland, 1900, p. 247, text fig. 6). Both ventral views, 
cartilage dotted. 
Ac, acetabulum; Hpipu, Epipubis; F.p.i, ischiopubic foramen; JI, ileum . 
Isch, ischium ; *, cartilaginous symphysis. 
ment and proportions of the carpalsin the Cheloniide and Dermochelys 
make convergence improbable in this case. 
4, The inner nares are bordered by the palatines and the vomer 
8 Compare Wieland, 1900, p. 246. 
® Volker (1913, p. 460) found a rudiment of the second, radial, central in the young 
Dermochelys. 
