Explanation of the Plate. 



PI. I. Atlantidae. 



Fig. 1. Oxy gvrus kerciudreni, Rang (X 8). a. in lateral view. 

 b. in dorsal view. 

 2. The same, operculum a. mytiloid centre of the oper- 

 culum (X 20) b. the whole operculum (X 20). 

 „ 3. The same, radula. a. (X 210), b. (X 80). 



4. Atlanta peronii, Rang, the whole animal in lateral view (x 8), 

 „ 5. Head of the same (X 20). 

 „ 6. Operculum of the same, a. (X 20), b. (X 40). 



7. Radula, (X 400), a. s. accessory spine. 



8. Atlanta fusca, Souleyet (X 20). 



9. Operculum of the same, (X 40). 



„ 10. Atlanta macrocarinata, n. sp. (X 8). a. in dorsal, b. in 



lateral view. 



, 11. The same (X 20). 



„ 12. Part of the radula (X550). a. s. accessory spine. 



„ 13. Operculum of the same (X 40). 



„ 14. Atlanta sp. Dorsal part of the operculum (X 40). 



„ 15. The same, radula (X 400). a. s. accessory spine. 



PI. II. Carinariidae. 



Fig. 16—17. Carinaria lamarcki, var. challenged n. var. Two 



specimens, nat. size. 

 „ 18. The same. Part of the head of. fig. 17, with eyes and 



tentacle (X 8). 

 „ 19. The same, swimming fin with sucker, s. Pedal ganglion, 



P- g- (X 8). 

 „ 20. The same, part of the body with nucleus, penis, P. and tail. 



CI. clasper-like organ of the tail. c. sp. cuticular sport, (X 8). 

 „ 21. The same, tail with clasper, (X 20). 

 „ 22. The same, radula. a. (x 400), b. c. (X 80). 

 „ 23. The same. Part of the body of the specimen in fig. 16. 



c. sp. cuticular spots, t. tubercles. P. penis, p. g. pedal 



ganglion, s. sucker (X 8). 

 „ 24. Tail of the same specimen. CI. clasper (X 8). 

 „ 25. Young specimen of the same species, (X 8). 

 „ 26. Cardiapoda richardi. Vayssiere. (X 8). 

 „ 27. The same. Radula (X 80). 



PI. III—V. Pterotracheidae. 



PI. III. Eupterotrachea hippocampus, Vayssiere. 



Fig. 28. E hippocampus, var. punctata, male, nat. size. 

 , 29. Head of the same. (X 8). 

 , 30. Part of the body of the same, with n. nucleus, g. gills, and 



o. osphradium. P, papilla of the female. 

 „ 31. The same. Buccal teeth, one of the two rows (X 80). 

 „ 32. The same. Penis (X 8). 

 „ 33. The same. Tail, showing the dorsal ridge continuing upon 



the horizontal tail fin (X 8). 



35. 

 36 



37. 

 38. 



39. 



Fig. 34 a— b. The same. Parts of the swimming fin. (X 8), a, base 

 of the fin, with cuticular spots (c. sp.) and pedal ganglion 

 (p. g.). b, border of the fin with sucker. 

 The same species var. apunctata. Base of the fin. 

 a — b. The same. Head of female in dorsal (a) and lateral 

 (b) view. Sp. cuticular spines. (X 8). 

 The same. Head of male; no cuticular spines. (X 8). 

 The same. Part of the body with N, nucleus, G, gills, and o, 

 osphradium (X 8). 

 Tail of the same (X 8). 



PL IV. 



Fig. 40. Heterodens gegenbauri. Vayssiere, nat. size, male. 

 „ 41. Head of the same (X 8). 



Part of the palate of the same, showing buccat teeth in two 

 longitudinal rows, b. t, and in front of these the peribuccal 

 teeth, p. t. 



Part of the body with nucleus (n), gills (g) and osphradium 

 (o) (X 8). 

 44 a — b. Parts of the swimming fin of a male (X 8). a. base 

 of the fin with pedal ganglion, p. g. b. border of the fin 

 with sucker. 



The same. Penis with seminal duct, surrounded by tubercles 

 (X8). 

 a — b. Two different views of the tail. The dorsal ridge is 

 not continued upon the horizontal tail fin. (X 8). 

 Eupterotrachea minuta. n. sp. Male, nat. size. 

 Head of same (X 8). 



Swimming fin of the same with sucker (s) and pedal 

 ganglion (p. g.) (X 8). 

 Buccal teeth (b. t.) of the same, (X 8). 

 Part of the body of the same, with nucleus (n), gills (g) 

 and osphradium (o), (X 8). 

 Penis of the same (X 8). 



42. 



43 



45. 



46 



47. 

 48. 

 49. 



50. 

 51. 



52. 



PI. V. 



Fig. 53. Eupterotrachea coronata, ForskSl, nat. size. 

 „ 54. The same. Part of the body with nucleus (n), gills (g) and 



osphradium (o). (X 8). 

 . 55. Head of the same (X 8). 

 „ 56. The same. Base of the swimming fin with cuticular spots 



(c. sp.) and pedal ganglion (p. g.) (X 8). 

 „ 57. Taii of the same (X 8). 

 . 58. Penis of the same (X 8). 

 „ 59. Row of buccal teeth of the same (X 80). 

 „ 60. Firoloida desmaresti, Lesueur, male, (X 8). 

 „ 61. The same. Nucleus and egg-chord (e. c.) of a female (X 20). 

 „ 62. The same. Nucleus and copulatory organ of a male (X 20). 

 „ 63. The same. Swimming fin with sucker (s) and pedal 



ganglion (p. g.) (X 20). 

 „ 64. The same. Head of a female (X 20). 

 „ 65. The same. Head of a male (X20). 

 . 66 a— b. The same. Parts of the radula (X 400). 



