181 277 



shells ("2). W. of Koh Chang, 20 fathoms, mud (1). S. of Koh Mak, 5-6 fathoms (1). 

 Koh Kahdat, 1 fathom, sand and corals (3). 



Long. 22—56 mm. 



Distribution:— Singapore (Danish Exped. to Siam, 2—3 fathoms, coral reef, 

 2 specimens), Andamans, Tranquebar, Ceylon, Mekran Coast, Persian Gulf, Aden, 

 Red Sea, Suez (50 m., Sturany). — Philippines, China, Japan, Amboina, Java, 

 New Guinea, Torres Strait. 



Cultellus (Ensiculus) cultellus L. var. marmoratus, Dunk. 



Ciiltellus marmoratus, Dunker, Proc. Zool. Soc. London, 1861, p. 423, No. 22. 

 Ensiculus — — Index raolluscor. mar. Japon., 1882, p. 174, pi. 7, fig. 24. 



Cultellus — — E. V. Martens, Süss- u. Brackwasser-MoU. d. Ind. Archipels, 1897, p. 271, 



No. 9. 



— — — Hidalgo, Fauna malacol. de I. isl. Filipinas, II, 1903, p. 23, No. 45. 



— {Ensiculus) maculatus, Preston, The Journal of Malacology, vol. XII. 1903, p. 8, pi. 2, fig. 36. 



N. of Koh Kahdat, 4—5 fathoms, coarse sand (1). Koh Kahdat, 1 fathom, 

 sand and corals (2). 



Long. 45 —52 mm. 



Distribution: — Cej'lon, Red Sea, Suez. — Japan, Philippines (?). 



I am convinced that C. marmoratus, Dunk., can scarcely be kept distinct 

 from the highly variable C. cultellus (even as a variety), but as the three specimens 

 which I have before me from the Gulf of Siam precisely agree with Dunker's diagnosis 

 and figure, I have given them as varieties. The specimens from Koh Kahdat were 

 taken under the same conditions and in the same locality as C. cultellus; in all the 

 three specimens from the Gulf of Siam, the valves, towards the posterior end, are 

 compressed in the middle, so that when viewed from the gaping, posterior end, 

 the latter has a placentiform outline. The darker colour and the concave dorsal 

 margin are also some of the characteristics of this form. 



Siliqua radiata L. 



Solen radiatus, Linné, Syst. nat., ed. X, 1758, p. 673. No. 28. - ed. XII, p. 1114, No. 38. — Mus. Ludov. 

 Ulricæ reg., 1764, p. 474, No. 16. 

 — — — CHEMNrrz, Conchyl. Cabin., VI, p. 54, pi. 5, figs. 38—39. 



Cultellus — — Sowerbv in Reeve, Conchol. icon., XIX, Cultellus, Sp. 13. 



Machaera radiata, Linné, Chenu, Manuel de Conchyl., II, 1862, p. 23, fig. 102. 



— — — Clessin in Martini u. Chemnitz, Conchyl. Cabin., XI Bd., 3 Abth., p. 59, No. 3, 



pi. 5, figs. 9-11. 

 Siliqua — — Mori.et, Journ. de Conchy]., vol. 37, 1889, p. 172, No. 8«. 



— — — Ed. v. Martens, Süss- u. Brackwasser-Mollusken d. Ind. Achip., 1897, p. 260. 



— — — Dautzenberg et Fischer, Journ. de Conchyl., vol. 54, 19U6, p. 220. 



Kampot (Golfe de Siam, L. Morlet). 



The Danish Expedition to Siam collected no specimens of this species. 

 Distribution:— Madras, Tranquebar, Ceylon, Gulf of Manaar, Bombay to 

 Ratnagiri, Mekran Coast. — Annam, Sumatra, Java, Flores, Celebes, Moluccas. 



