BY T HARVEY JOHNSTON AND O. W. TIKGS. 229 



tt.c, uterine cavity: ut., uterus; n.i., inner part of uterus; u.o., outer part 

 of uterus; n.n., funnel (nephrostome) of uterus, communicating with the 

 ccelome; v. b. v., ventral blood vessel: v.d., vas deferens; v.g.p., ventral 

 groove of proboscis; v.n.c, ventral nerve cord; v.s., vesicula seminalis; 

 x., nervous(?) tissue associated with dorsal blood vessel of proboscis; //., 

 pit surrounding uterine openings. 



EXPLANATION OF PLATES IX. XI. 



Plate ix. 



Fig.l. — Female of Pseudobonellia biuterina; ventral view (slightly mag- 

 nified). 



Fig.2. — Female, showing anatomy ( x about 3). The uteri were empty in 

 the specimen figured. 



Fig. 3. —Setae. 



Fig.4. — Sketch showing relations of uteri, male tube, oesophagus and 

 nerve cord. 



Fig.o. — Portion of proboscis (diagrammatic). 



Fig, 6. — T.S. proboscis. 



Fig.7. — Rectum and anal funnels. 



Plate v. 



Fig.S.— T.S. body wall of female, 



Fig.9. — Body showing male tube, two parts of a uterus, two intestinal 



loops, and the siphon. 

 Fig. 10. — Part of intestinal wall witli associated siphonal folds with which 



the siphon becomes subsequently connected. 

 Fig. 11. — As in Fig. 10, but showing the siphon in process of fusion with 



the siphonal folds. 

 Fig. 12. — Uterus, side view, diagrammatic. 

 Figs. 13, 14. — Two views of posterior nephridial tidies. 

 Fig. 15. — Two sections across such tubes. 

 Fig. L6a, b, c, d, e. — Successive stages in the development of the ovum; 



c shows section through stage l> 

 Fig. IT. — Developing sperms. 



Plate xi. 



Fig. 18. — T.S. andrcecium and associated structures (female body wall. 



uterus, nerve). 

 Fig. lit. — T.S. andrcecium and male. 

 Fig.'iH. — Oblique longitudinal section of body wall, andrcecium and male, 



showing mode of attachment of the posterior end of the male to the 



distal portion of the male tube. 



18 



