I30 



VERTEBRATE SKELETON 



anterior border of the vomer. In the lower jaw angulare and articu- 

 lare fuse as do dentale and splenial. The angulare extends back 

 over the posterior process of the Meckelian. Some genera have 



Fig. 138. — Skull of Ichthyophis (Sarasins, '90). an, angulare; ba, basal;/, frontal; 

 gt, groove for tentacle; mp, maxillo-palatine; n, nasal; ops, otic process of suspensorium; 

 p, parietal; pf, postfrontal; pm, premaxilla. prf, prefrontal; so, supraorbital; st, 

 stapes; t, Sarasins' turbinal (septomaxillary). 



teeth which are apparently both dentary and splenial in origin. The 

 other visceral arches of Cascihans (fig. 139) are greatly simphfied or 

 even degenerate when compared with those of other Amphibia. 



Fig. 139. — Hyobranchial skeletons of Epicrium (Sarasins, '90). A, of larva; B, adult. 



Anura, although usually regarded as higher than Urodeles or 

 Gymnophiones, have a skull more primitive in many respects, this 

 appearing especially in the more complete retention of the chondro- 



