THE NEPHEIDIA OP THE POLTCH^.TA. 



725 



Diagrams illustrating the relation between the genital funnel and the 

 nephridiuna in the Polychseta : A, hypothetical form with separate 

 genital funnel and protonephridium ; B, Phyllodocidse and Goniadse ; 

 C, Nephthyidse ; B, Dasybranchus caducus; B, Dasybranchus 

 gajolse and Tremomastus; F, Nereidse ; Q, Hesione; ZT, Irma; I, 

 Syllidse, Spionidse, Terebellidse, etc. The nephridium is drawn with 

 thick black lines, the genital funnel is shaded with thin cross-lines. The 

 small circles represent ripe ova. 



