286 



PL A TIIELMINTIIES. 



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

 Areliigetes in annelids (Samuris). 



Family 2. LIGULID.E. No acetabula; numerous sexua.l organs, but no 

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

 in the intestine of birds. Ligtila. 



FIG. 248 



FIG. 350. FIG. 



FIG. 248 Cysticercoid in invaginated and/extended condition from Arion ater* 

 (From Hatschek.) 



FIG. 249.Ca 1 ryophyllceusmutabilis. (After M. Schultze.) df, vasdeferens; dv, vitelline 

 duct; fc, scolex; ov, ovaries; ps, penis; v.s, vagina with receptaculum seminis; f, 

 testes; nt, uterus; vi\ yitellarium ; v.s, yesicula seminalis. The connexion of 

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

 lacking in the figure. 



FIG. 250. Tapeworms of fishes. (After Linton.) A, Echinobothrium variabile *; B, 

 Rynchobothrium bisulcatum * ; C\ Tetrabotkrium* 



Family 3. TETRARHYNCHID.E. With scolex and proglottids, the head 

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

 stages in fishes. Tetrarhynchus, Rynchobothrium.* 



Family 4. TETRAPHYLLID^E. Head with four very mobile suckers, often 

 armed with hooks. Echinobothriiun * (fig. 250), Acanthobothrium.* 



