286 



PL A TIIELMINTIIE8. 



in the intestine of cyprinoids; Amphilina in body cavity of sturgeon; 

 Archigetes in annelids {Sanuris). 



Family 2. LiguliDjE. No acetabula; numerous sexual organs, but no 

 proglottids. The immature stages in the body cavity of fishes, the adults 

 in the intestine of birds. Liyula. 



Fig. 248 



Fig. 25(J. Fig. MB. 



Fig. 248 — Cyst.ioerfoid in invaginated and^fextended condition from Arlon ater, 

 (From Hatschek.) 



Fig. 249. — Caryoj'hyUo^usmuiahiJis. (After M. Schultze.) df, vasdeferens; dv, viteliine 

 duct: fc, scolex; oi', ovaries; p.s, penis; vs, vagina witli receptaculiini seminis; /, 

 ti'stcs; lit, uterus; vi, viteilarium ; I'.s, vesicula seminalis. Tlie connexion of 

 vagina with tile crossing point of genital duct, vitelline duct, and uterus is 

 lacliing in the figure. 



Fig. 2.50.— Tapeworms of fishes. (After Linton.") -4, Echinohothrium variabile*; By 

 Ri/nchobutlirlum bisulcatitm * ,' C\ Tetrabothriuiii* 



Family 3. Tetrarhynchid.f. With scolex and proglottids, the head 

 with four protrusible hooked pvoliosces (fig. 241). Immature and mature 

 stages in fishes. Tetrarliyii.cluis, ]\'i/iichohot7iriiiin.* 



Family 4. Tetrafiiyllid.f,. Head -with four very mobile suckers, often 

 armed with hooks. EchinohotliriiiDi * (fig. 250), Acaiithobothrium.* 



