NUDIBRANCHIATE GASTEROPODA. 47 



Deiulronotus robust us, Verrill. 



Fig. 27. The rhinophore with its sheath and club. 



— 28. The tongue from above with the radula-sheath shining through and with the upper end of 



the radula. 



— 29. a Seminal duct, b glans penis projecting from the bottom of the praeputium. 



PL IV. 



Deiulronotus robust us, Verrill. 



The fore end of the animal. 



The tail of the animal. 



Elements of the prehensile ring, x 350 diam. 



Fig. 1 



— 2 



— 3 

 4 



— 5 



A median tooth, from above, x 200 diam. 



The outer end of a series of teeth, a the outermost tooth, b the edge of the radula. x 350 diam. 



Gonieolis atypica, Bgh. 

 Fig. 6. The fore end of the animal, from the right side, with a tentacles, b rhiuophores, and c dorsal 

 papillae; with the genital aperture, the renal pore, d anal papilla, and c foot-brim. 



— 7. The fore end, from above; aa, c as in fig. 6. 



— 8. The central nervous system, from above, drawn with cam. luc; a Ganglia cerebro-pleuralia, 



bb Ganglia pedalia, cc Ganglia olfactoria, dd G. buccalia and gastro-oesophagalia, e commis- 

 sura subcerebralis, f comm. pleuralis, g coram, pediaea. 



— 9. The mandibles from the fore side. 5/ T . 



— 10. The hinge-part of the right mandible, from before. 



— 11. A piece of the masticatory edge, a fore edge. X 350 diam. 



— 12. Median tooth-plates from above. 



— 13. Lateral tooth-plate, from the radula. 



— 14. Worn foremost (oldest) lateral tooth-plate. 



Figs. 12 — 14 drawn with cam. luc. x 200 diam. 



— 15. Lateral tooth-plate, x 250 diam. 



Gonieolis intermedia, Bgh. 

 Fig. 16. From the middle part of the radula, a median plate, b lateral plate. 



— 17. A similar piece, lateral view, a and b as in fig. 16. 



Figs. 16 — 17 drawn with cam. luc. x 350 diam. 



Coryphella salmonacea (Couth.). 

 Fig. iS. Excretory duct of the Gland ptyalina? x 100 diam. 



— 19. Lateral teeth, x 350 diam. 



