338 EXPLANATION OF PLATES, XVII. 



PLATE 2. 



FIGURE PAGE 



16-18. D. octangulatum Don. FromLischke, . / , . 16 



19. D. japonicum Dkr. From Dunker, . . 1 . .17 



20, 21, 23, 24. D. hexagonum Gld. From Lischke, ' , . 1& 

 22. D. octangulatum Don. Specimen, . . . . . 16 



25. D. bisexangulatum Sowb. Thes. Conch., . . ^ . 15 



26. D. weinkauffi Dkr. From Dunker, . . . ., . 40 



27. D. sexcostatum Sowb. Specimen, . ; . . ^ ,. . 19 



28. D. sexcostatum Sowb. From Thes. Conch., . *%.' . 19 

 29-31. D. yokohamense Wats. From Challenger Zool., . . 16 



PLATE 3. 



32. D. rectum Gmel. From Conch. Icon., . . . .252 



33. D. rectum Gmel. Specimen, . . . . ..,,.- . 252 



34. D. rectum Gmel. From Thes. Conch., ... . , . 252 



35. D. vernedei Hani. Specimen, . . r , . . .80 



36. 37, 38. D. diarrhox Wats. From Chall. Zool., . . 109 

 39-41. D. tornatum Wats. From Chall. Zool., . . . 121 



41. D. ceras Wats. From Chall. Zool., . . . . . 68 



42, 43. D. vernedei Hani. From Thes. Conch., . , . 80 

 44-46. D. leptoskeles Wats. From Chall. Zool., . . 110 



PLATE 4. 



47. D. pseudosexagonum Dh. From Deshayes, . . . 23 



48. D. pseudosexagonum Dh. From Thes. Conch., . .23 



49. D. javanum Sowb. From Thes Conch., . . .4 



50. D. quadrapicale Sowb. From Thes. Conch., . . .34 



51. D. tesseragonum Sowb. From Thes. Conch., . . . 34 



52. D. dispar Sowb. From Thes. Conch., ... .32 

 53-56. D. dispar Sowb. Specimen, . . . . . 32 

 57-60. D. di psyche n. sp. Specimen, . .. . .33 



PLATE 5. 



61-65. D. fisheri Stearns. Type specimens, . . . . 36 



66-68. D. letsonse n. sp. Type specimen, . . . . 4 



69, 70. D. strigatum Gld. Type specimen, . . . . 13 



71, 72. D. americanum Ch. From Chenu, .' . 22 



73. D. laqueatum Verr. Specimen, . . . * . . 10 



74-76. D. buccinulum Gld. Type specimen, . . . .14 



77. D. quadrangulare Sowb. From Thes. Conch., . . . 35 



PLATE 6. 



78, 79. D. delessertianum (^rectum). From Chenu, . .252 

 80. D. porcatum Gld. From Thes. Conch., . . . .15 



