338 EXPLANATION OF PLATES, XVII. 



PLATE 2. 



FIGURE PAGE. 



16-18. D. octangulatum Don. From Lischke, . . . 1ft 



19. D. japonicurn Dkr. From Dunker, . . . . . 17 



20, 21,23, 24. D. hexagonum Gld. From Lischke, . . 18 

 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, 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, .... 



57-60. D. dipsyche 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, . 



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- 



