40 t. b. eosseter on tape-worms. 



Explanation of Plates 5 and 6. 

 Plate 5. Hymenolepis nitida, Krabbe. 



Pigs. 1 — 3. Three sections of strobila (? abnormal), x 70. 

 ,, 4 — 9. Six sections of strobila (normal) : Fig. 4, x 35 ; 

 Figs. 5 — 9, x 70 (Fig. 8, male ; 9, female). 



Male segment : exb, expulsion-bladder ; cp, 

 cirrus-pouch ; c, cirrus ; vd, vas- deferens ; ve, 

 vasa-efferentia ; ttt, testes. 



Female segment : v, vagina ; vc, vaginal canal ; 

 rs, receptaculum seminis ; oo, proximal and distal 

 ovaries ; yg, yelk-gland. 



Fig. 10, anterior, and Fig. 11, posterior portion of expulsion- 

 bladder, x 700. Lettering as above ; vdi, vas- 

 deferens interior. 



Figs. 12 — 14. Spinous vaginal pore, x 700: Fig. 12, in situ-, 



Fig. 13, as seen in somewhat crushed segment 

 showing aperture and vestibule of pore; Fig. 14, 

 tilted specimen with emergent vaginal canal. 



Fig. 15. Receptaculum seminis — the " cirrusblaeren " of 



Krabbe — x 140. 

 ,, 16. Oncosphere or six-hooked brood (after Krabbe, 



x 240). 



Plate 6. Hymenolepis nitidulans, Krabbe. 



Figs. 1 — 13. Composition of the strobila and formation of the 



segments, x 70 : Fig. 1, scolex with hooks and 

 suckers, neck and early segmentation ; Figs. 

 6 — 11, development of male genitalia (Fig. 11 : 

 ttt, testes ; vs, vesicula seminalis ; vd, vas- 

 deferens ; pgs, prostatic glandular sac ; c, cirrus 

 in act of protrusion from pore ; cp, cirrus-pouch) ; 

 Fig. 12, female genitalia (v, vagina; vc, vaginal 

 canal; i's, receptaculum seminis; oo, ovaries; 

 yg and sg, yelk- and shell- glands) ; Fig. 13, 

 uterine segment. 

 ,, 14. Prostate glands dissected from muscular sac, x 70. 



„ 15. Hook from scolex, x 350. 



Jour -a. Quekett Microscopical Club, Ser 2, Vol. X., No. (30, April 1907. 



