PHYLUM CHORDATA 



387 



lab 



pro.pt 



bas.br 



FIG. 217. Skeleton of Sting-Bay (Urolophu* testaccus), ventral view. a.i>. p. 

 anterior vertebral plate ; bus. br. basi-branchial plate ; br.^-br.^ branchial arches. 

 The branchial rays are represented as having been removed, the round dots in- 

 dicate their articulations with the arches, cl. skeleton of clasper ; h. jft. hyo- 

 mandibular ; hy. hyoid arch ; lab. labial cartilage ; lig. ligament connecting the 

 hyomandibular with the palato-quadrate and Meckel's cartilage ; Hick. Meckel's 

 cartilage ; ms. pt. mesopterygium ; int. pt. metapterygium of pectoral fin ; 

 mt.pt '. metapterygium of pelvic fin ; nas. nasal cartilage ; pal. palato-quadrate ; 

 pcct. pectoral arch ; //. pelvic arch : pro. pt. propterygium ; sp. spiracular 

 cartilage. 



C C 2 



