PLATE XIY. 
Figs. 1-15. Bathydoris abyssorum, Bergh. 
Figs. 1, 2. Papillae of the back. 
Fig. 3. A similar papilla; a, openings of the vessels and nerves. 
Fig. 4. The central nervous system, from above ; a, a, the cerebral ganglia ; b, b, the two portions of 
the right pleural ganglion ; c, pedal ganglion ; d, the intercerebral and interpleural com- 
missure ; e, e, the cerebro-buccal connective; /,/, buccal ganglia; g, interbuccal commis- 
sure ; li, common commissure. Cam. luc. 
Fig. 5. Nerve ramification in the subcutaneous layer. Cam. luc. x 55 diam. 
Fig. 6. a, The median plate; b, the first, and c, the second, lateral plate. Cam. luc. x 100 diam. 
Fig. 7, 7. Part of the rhachis with four plates. Cam. luc. x 100 diam. 
Fig. 8. First lateral plate of two series, from the side. Cam. luc. x 100 diam. 
Fig. 9. Outer part of a series of plates (of the radula sheath) with nine plates, from the side ; a, 
outermost. Cam. luc. x 100 diam. 
Fig. 10. Outer part of two series of plates with nine and twelve plates, from above; a, a, the outer- 
most. Cam. luc. x 100 diam. 
Fig. 11. The hermaphrodite gland, from the under side, with the chief duct. 
Fig. 12. Lobule of the gland. 
Fig. 13. Zoosperm ; a, head. 
Fig. 14. a, Yas deferens; b, prseputium; c, point of penis. 
Fig. 15. Penis opened, with continuation of a, vas deferens out to the point c. 
Glaucus atlanticus (Forster). 
Fig. 16. Part of the margin of the processus masticatorius ; a, behind. Cam. luc. x 750 diam. 
Figs. 17, 18. Tritonia chcdlengeriana, Bergh. 
Fig. 17. Two lateral plates, obliquely from the inner side. Cam. luc. x 350 diam. 
Fig. 18. A similar plate, more obliquely from the outer side. Cam. luc. x 350 diam. 
Figs. 19, 20. Marionia occidentalis, Bergh. 
Fig. 19. Masticatory plates of the stomach. Cam. luc. x 55 diam. 
Fig. 20. One of the smallest plates. Cam. luc. x 55 diam. 
