282 



ZOOLOGY 



SECT- 



the corresponding clavicle : there is some reason for thinking it 

 to be homologous with the bone usually called clavicle in 

 Teleostomi. 



In the pelvic girdle of the Urodela the combined pubic and 



ischiatic regions 

 (Fig. 897, P, Is} 

 of the right and 

 left sides are 

 united to form an 

 elongated cartila- 

 ginous plate which 

 gives off on each 

 side, above the 

 acetabulum (G), 

 a slender vertical 

 rod, the ilium 

 (II 1 ). Ossifica- 

 tions are formed 

 in the iliac and 

 ischiatic regions, 

 but the pubic re- 

 gion remains car- 

 tilaginous. There- 

 semblance of the 

 pelvis of the lower 

 Urodela, and es- 

 pecially of Nec- 

 turus, to those of 

 Polypterus(p. 216) 

 and of the Dipnoi 

 (p. 233) is note- 

 worthy. 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, the epi- 

 pubis (Ep). It is developed independently of the pelvis, and its 

 relations to that structure are very similar to those of the sternum 

 to the shoulder-girdle ; it has, in fact, been proposed to call it a, 

 pelm-stemum. 



FIG. 896. 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) 

 coracoid ; q pro-coracoid ; Co. (in A), coracoid ; (t. (in A) 

 glenoid cavity ; L, its cartilaginous edge ; Pf (in A), glenoid 

 cavity ; ,. scapula -88. supra-scapula ; sternum ; * f Serve 

 foramina. (From Wiedersheim.) 



