338 



EXPLANATION OF PLATES, XVII. 



Plate 2. 



FIGURE 



16-18. D. octaiigulatum Don. From Lischke, 



19. D. japonicum Dkr. From Dunker, . 



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

 22. D. octaugulatam Don. Specimen, . 



25. D. bisexaugulatum Sowb. Tlies. Conch., . 



26. D. weinkauffi Dkr. From Dunker, . 



27. D. sexcostatum Sowb. Specimen, 



28. D. sexcostatum Sowb. From Thes. Conch., 

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



Plate 3. 



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



33. D. rectum Gmel. Specimen, .... 



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



35. D. vernedei Hani. Specimen, .... 



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

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



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



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

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



Plate 4. 



47. D. pseudosexagonum Dh. From Deshayes, 



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



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



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



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



52. D. dispar Sowb. Fi'om Thes. Couch., 

 53-56. D. dispar Sowb. Specimen, 

 57-60. D. dipsj'^che n. sp. Specimen, 



Plate 5. 



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



66-68. D, letsonae n. sp. Type specimen, 



69, 70. D. strigatura Gld. Type specimen, 



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



73. D. laqueatum Verr. Specimen, 



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



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



Plate 6. 



78, 79. D. delessertianum (=rectum). From Chenu, 

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



252 

 15 



