PLATE XII. 
Figs. 1-8. Tritonia challengeriana, Bergli. 
Pig. 1. First lateral plate, from above. Cam. luc. x 350 diam. 
Fig. 2. A lateral plate, from the outer side. Cam. luc. x 350 diam. 
Fig. 3. Another, seen (shortened) from the inner side. Cam. luc. x 350 diam. 
Fig. 4. Another, from the side. Cam. luc. x 350 diam. 
Fig. 5. The broken point of the hook of a lateral plate. Cam. luc. x 350 diam. 
Fig. 6. The outer part of four series with one to three plates; a, a, outermost. Cam. luc. x 350 diam. 
Fig. 7. a, Benal syrinx ; b, root of the duct of the organ. 
Fig. 8. a, Spermatheca ; 5, its duct ; c, the vagina. 
Figs. 9-13. Cuthonella abyssicola, Bergh. 
Fig. 9. a, Anus ; b, renal pore ; e, upper end of two series of papillae belonging to the second group. 
Fig. 10. Genital papilla with end of the glans ; behind this the vulva (vagina) and aperture of the 
duct of the mucous gland. 
Fig. 11. Basal plate of a lingual plate, from the under side. Cam. luc. x 350 diam. 
Fig. 12. The point of the hook, from above. Cam. luc. x 350 diam. 
Fig. 13. Two plates, from the side. Cam. luc. x 350 diam. 
Figs. 14-20. Bathydoris abyssorum, Bergh. 
Fig. 14. Fore-end of the animal, from the under side ; a, a, rhinophoria ; b, sole of the foot; c, genital 
papilla, with the praeputium (and the point of the glans penis) and the aperture of the 
duct of the mucous gland. Natural size. 
Fig. 15. Hinder end of the animal ; a, a, sides of the body ; b, sole of the foot. Natural size. 
Fig. 16. Part of the skin of the back with papillae. 
Fig. 17. A lateral tooth of the outer half of a row, from above. Cam. luc. x 100 diam. 
Fig. 18. Similar, from below. Cam. luc. x 100 diam. 
Fig. 19. Four lateral plates from the outer sixth part of a row, obliquely from the outside ; a, the outer. 
Cam. luc. x 100 diam. 
Fig. 20. Penal tubules, from the peritoneum. Cam. luc. x 100 diam. 
