39 135 



Brachyodontes emarginatus, Bens. (Reeve). 



Modiola emarginatus, Benson, M. S. in Mus. Cuming. 



— — — Reeve, Concliol. icon., X, Modiola, Sp. 60, pi. X, fig. 73. 



Perna emarginata, — Rochkbuune, Faune inalacol. de la Cochinchine et du Cambodge, Suppl., 



Bullet, de la Soc. philomath, de Paris, '"lu 1881, (Repr.) p. 4, No. 17. 

 Modiola — — P. Fischer, Catal. d. Moll. de llndo-Chine, p. 212. 



— — — Martini u. Chemnitz, Conehyl. Cabin., VIII, 3 Abth., p. 114, pi. 20, fig. 3 



(according to v. Martens not p. 120, pi. 25, figs. 7 — 8, these probably being 

 M. Fortunei, Reeve). 



— — — V. Martens, Süss- u. Brackwasser Moll. d. Ind. Archipels, 1897, p. 227. 



Koh Kahdat, 1—5 fathoms, sand (3). Strand of Koh Kahdat (fragments). 



Long. 25 mm. 



Distribution: — The coast of Birma, in brackish water (Blanford), Bom- 

 bay (Melvill & Abercrombie), Calcutta (v. Martens), Poulo Condor (Rochebrune), 

 Philippines (Elera). 



Septifer bilocularis, L. 



Mytilus bilocularis, Linné, Systems Nat. ed. X, 1758, p. 705, No. 212. — ed. XII, p. 1156. — Mus. Ludov. 



Ulricæ, 1764, p. 540. 

 Tichogonia — — Martini u. Chemnitz, Conchyl. Cabin., VllI Bd., 3 Abth., p. 10, pi. 2, figs. 11—17. 



Septifer — — Dunker, de Septiferis gen. Mytilaceorum et de Dreisseniis, 1855, p. 6. 



— — — Edg. a. Smith. Challenger E.xp. Lamellibranchiata, 1885, p. 271. 



— — — P. Fischer, Catal. d. Moll, de I'lndo Chine, p. 214. 



— — — Dautzenhkrg & Fischer, Journ. de Conchyl., vol. 53, 1905, p. 450. 

 Mytilus Nicobaricus, Chemnitz, Conchyl. Cabin., Vlll, 1785, p. 155, pi. 82, figs. 736-37. 



— — — Reeve, Conchol. icon., X, Mytilus, Sp. 42. 



Very commonly distributed between Koh Kram and Koh Kut, 1 — 30 fathoms, 

 sand, shells, mud and gravel; between old coral blocks. 



Long. 3—48 mm. 



Distribution: — Singapore, Strait of Malacca, Nicobars, Andamans, Aracan 

 coast, Ceylon, Mahlos Atoll (Maldive Archip.), Persian Gulf, Red Sea, Seychelles, 

 Amirautés, Madagascar, Mascarene Isis., Querimba Isis., Zanzibar, Mozambique, Natal. 

 — Poulo Condor, China, Tonkin, Hongkong, Japan (Nagasaki), Philippines, Sumatra, 

 Christmas Isl., Celebes, Sulu Isis., Moluccas, Sunda Isis., Aru Isl., Sorong, New Guinea, 

 Salomo Isis., Torres Str., East Australia, New Caledonia, Marianne Isis., Viti Isis., 

 Paumotu Isl. 



This species, which varies greatly, both in regard to colour and form, has 

 presented to many authors the temptation of forming new species. Edg. Smith, in 

 his report of the Lamellibranchiata of the Challenger Expedition (p. 271), has 

 enumerated various synonyms, and undoubtedly some more maj' be added. Jukes- 

 Browne' gives the gen. Septifer as a sub-genus of Brachyodontes. 



• Proc. Malacolog. Soc. London, vol. VI, 1905, p. 223. 



