II Post, dorsal 



d, Piece of the intestine show 

 ovd, point of union of female 

 I), "ootype" or chamber into 

 uterus (ut) of Diporpa I ; uto, 

 deferens, permanently inserted 

 yolk -glands. 



FIG. 27. A, Egg of Dip- 

 lozoon paradnxum v. 

 Nord., consisting of a 

 shell enclosing or, the 

 actual ovum, sur- 

 rounded by yc, the 

 yolk -cells ; B, larva 

 just hatched ( x 125) ; 



C, two Diporpa (I 

 and II) about to unite ; 



D, conjugation in pro- 

 gress but not yet 

 complete, dt, Do7-sal 

 papilla ; e, eye ; g, in- 

 testine ; m, mouth ; sc, 

 ad-oral sucker ; th, 

 spirally-wound thread 

 attaching the egg to the 

 gill of the Minnow ; 

 vs, ventral sucker ; (in 

 D) I, I, one Diporpa, 

 ventral view; II, II, 

 the other, dorsal view. 

 (After Zeller.) 



FlO. 28. Hinder part of the 

 body of Diplozoon para- 

 doxum. The fusion of the 

 two Diporpa, where they 

 come into contact, is now 

 complete. They now cross 

 each other like an X, and 

 are twisted, so that Diporpa 

 I, in front of the point of 

 fusion, is seen from the 

 dorsal surface ; behind, 

 from the ventral surface ; 

 and the reverse is the case 

 with Diporpa II. The 

 compound animal is seen 

 from the opposite surface 

 to that shown in Fig. 27, 

 D. The digestive and 



omitted. (After Zeller.) I 

 Ant. dorsal, dorsal surface 

 of Diporpa I, facing the 

 anterior end ; I Post, 

 ventral, ventral surface of 

 Diporpa I, posterior end ; 

 I Post, ventral and similarly for II Ant. 



ventral and II Post, dorsal. 



ng opening of, gic, vitello-intestinal canal ; ov, ovary ; 



genital ducts ; sc, suckers ; te, testis ; ut (in Diporpa 



which shell-glands open. This is continuous with the 

 ventral opening of uterus ; vay, vagina, with vd, vas 



into it through the genital pore ; yd, yolk-ducts ; yg. 



