XIII 



PHYLUM CHORDATA 



303 



ilium (II). Ossifications are formed in the iliac and ischiatic 

 regions, but the pubic region remains cartilaginous. The re- 

 semblance of the pelvis of the lower Urodela, and especially of 

 Necturus, to that of Polypterus (p. 232) and of the Dipnoi 



FIG. .:>L -A, right side of shoulder-girdle of Salamandra ; B, shoulder-girdle and sternum 

 of Amblystoma (Axolotl) from the ventral aspect, a, b, processes of scapula ; C (in B), 

 c-oracoid ; (.'/. procoracoid ; Co. (in A), coracoid ; G. (in A), glenoid cavity; L, its cartila- 

 ginous edge ; Pf (in B), glenoid cavity ; S. scapula ; SS. supra-scapula ; st. sternum ; *, t, 

 nerve foramina. (From Wiedersheirn's Comparative Anatomy.) 



(p. 250) is noteworthy. In Anura the pelvic girdle resembles that 

 of the Frog. 



Attached to the anterior border of the pubic region there occurs 

 in many Urodela and in Xenopus a rod of cartilage, forked in front, 



