CYCLOSTOMATA 



and two small posterior cartilages, while a special plate supports 

 the rows of horny teeth (Fig. 23). 



Z.' ^ 5 - i 



s a o i." 



~5-B.= i:- 1 -" 



si^lsrf 



e = ^ S - 

 a .. .= - 

 - .. -.x p... 



"s.So^-^ 

 '- "" 7 - 



1^1? 



"^3 5 " " a; ^ *"* 



llflh" 



C^^S"--^ 

 :- ^f. g ..^a 



Many attempts have been made to compare the skull and 

 visceral skeleton of the Cyclostome with those of the Gnathostome ; 

 but none of these has proved very successful in detail. The com- 



