242 



P. H. EDGEAVOKTH. 



The development of the branchial muscles of Ceratodiis, as 

 given by Greil, is summarised above (pp. 175 and 176). In the 

 specimens examined the lower ends of the branchial niyotomes 

 separate from the lateral wall of the cephalic coelom in stage 

 42 (Text-figs. 42, 43). In stage 46 the lower end of the first 

 branchial myotome grows forward to the hypohyal (Text-fig. 

 44), forming the interarcualis ventralis I^ s. bi-anchio-hyoideus; 



Text-fig. H:i. 



cwlu^ui, _ 



<^UA<J- C^ 



cei,.\\*^. oji-j 



k^ptjUsi iJmvoj... 63. 



Alytes. hirvH I'J nun., transverse section. 



in the second, third, and fifth branchial segments the lower ends 

 of the myotomes grow downwards, forming coraco-branchiales 

 II (Text-fig. 47), III and V, and. also downwards and inwards, 

 forming the (lateral halves of the) transversi ventrales 



' Cerato-hyoideus hiternns of Fi'irltrinyer : cenito-liyoidens of Greil ; 

 M. ^rand abductenr dn premier arc hrancliial of Jaqnet. who states 

 that the liind end of the mnscle is attached to the iir.st and second 

 branchial l^ars. 



