PLATE X. 
Figs. 1-3. Cuthonella abyssicola, Bergli. 
Fig. 1. The left mandible, from the outside, without being pressed ; a, hinge with crista connectiva 
(on the inner side) ; b, end of processus masticatorius ; c, the posterior limit of the succen- 
turiate buccal cavity (Neben-mundhohle). Cam. luc. x 55 diam. 
Fig. 2. aa, The ejaculatory duct ; b, side-duct from a gland (?) ; cc, the base of the praeputium ; 
d, glans penis; e, point of the penis. Cam. luc. x 55 diam. 
Fig. 3. a, Spermatheca ; b, duct of the same ; c, opening in the vestibulum. Cam. luc. x 55 diam. 
Fig. 4. Acura pelagicct, Adams. 
Fig. 4. The heart and the renal sac ; a, pericardium ; b, the atrium of the heart, and c, the aorta ; 
d, renal syrinx ; e, e, the renal chamber ; /, the ureter. Cam. luc. x 55 diam. 
Figs. 5-17. Distomum glauci, Bergli. 
Fig. 5. The animal, from the under side ; a, the oral, b, the ventral, sucker ; c, the aperture through 
which the tail is retracted ; the cavity of the body nearly filled with yellow cells (eggs). 
Cam. luc. 
Fig. 6. Another individual in the same position ; a and b, as above ; c, the tail (with its retractors). 
Cam. luc. 
Fig. 7. Another individual, from the side ; a, b, c, as above ; behind the oral sucker the genital 
papilla, along each side of the body the branch of the intestine. Cam. luc. 
Fig. 8.' Another individual, in similar position ; a, b, c, as above ; in the tail the branches of the 
intestine and the two egg-sacs. Cam. luc. 
Fig. 9. The anterior half of an individual ; a, the oral sucker ; b, the genital papilla ; c, the ventral 
sucker along the sides of the body the branch of the digestive channel (d). Cam. luc. 
Fig. 10. A small individual -without tail. Cam. luc. 
Fig. 11. a, The oral sucker ; b, b, the branches of the digestive channel ; c, the two anterior branches 
of d, the excretory organ ; e, the ventral sucker ; /, the vesicula seminalis. Cam. luc. 
Fig. 12. a, The left branch of the digestive channel ; b, end of the excretory duct; c, c, the posterior 
end of the branches of the digestive channel (in the half-protruded tail). Cam. luc. 
Fig. 13. Anterior end of the animal, with a, the oral sucker, and b, the genital papilla. Cam. luc. 
Fig. 14 Another similar in somewhat different position. Cam. luc. 
Fig. 15. The ventral sucker, from the side. Cam. luc. 
Fig. 16. The genital papilla, with the penis covered with small prominences. Cam. luc. 
Fig. 17. An egg. Cam. luc. 
