MORPHOLOGY OF CRAN[AL MUSCLES IN SOME VERTEBRATES. 293 



parts also occurs in Teleostomi and Sauropsidii; backward 

 extension of botli hyoid myotome and interhyoideus to form 

 a dorso-ventral sheet also occurs in Ceratodus and Teleo- 

 stomi (though in these, in an opercular fold) formation of 



Text-fig. 91. 



LooL mx 







Text-figs. 91-93.— Rabbit, emlnyo 9 mm. ; Text-fig. 91 through 

 the mandibular segment, Text-figs. 92 and 93 through the 

 hyoid segment. 



coraco-branchiales and of a coraco-mandibularis also occurs 

 in Ceratodus and some Teleostomi; non-formation of levatores 

 arcuum branchialium, and the associated method of develop- 

 ment of the trapezius occurs in Sauropsida and rabbit. 



