134 38 



falhonis, soll clay (1). W. of Koh Chang, 20 falhoms, clay (1). S. of Koh Kahdat, 

 8—10 fathoms, mud (2). W. of Koh Kiit, 30 falhoms, sand and mud (1). 



Long. 4—35 mm. 



Distribution: — Mergui Arcliip., Suez. — Canton, Easl Australia (the districts 

 around Sydney). ' 



The specimens from the Gulf of Siam are all provided with a very shiny, 

 greenish epidermis and several were either completely or partly hidden in their 

 "nest" of byssus-threads, and fragments of shells, pebbles, etc. were partly attached 

 to and partly entangled in these threads. Modiola perfragilis, Dunk.,- M. Japonica, 

 Dunk., M.angusta, Cless.,' and M. cultelhis, Desh., ' are closely allied species. Pro- 

 fessor Ed. v. Mautens, to whom I sent some specimens of the present species from 

 Koh Samit, writes as follows: "Modiola perfragilis "Reeve" von d. Molukken ist 

 wohl Jugendzustand von glaberrima." 



Brachyodontes (Hormomya) subramosus, Hanl. 



Modiola subramosa, Hanley, Proc. Zool. Soc. London, XII, 1844, p. 14. 



— — — Catalogue of rec. bivalve shells, 1842—56, p. 241, pi. 24, fig. 30. 



— — — Rkkve, Conchol. icon., X, Modiola, Sp. 43. 



— — — Martini u. Chemnitz, Conehyl. Cabin., VIII, 3 Abtli., p. 121, pi. 31, fig. 11. 



— — — V. Martens, Süss- u. Brackwasser Moll. d. Ind. Archip., 1897, p. 226. 



— ramosa, Clessin, Martini u. Chemnitz, Conehyl. Cabin., Vlll, 3 Abtli., p. 134, pi. 26, fig. 8. 



West coast of Koh Chang, 1 fathom, old coral blocks (4). Koh Kahdat, 1 

 fathom, sand (1). 



Long. 7 mm. 



Distribution: — Mindanao and Samar, Philippines (Cuming and Jagor), 

 Ternate, Moluccas (Dunker's collect.), Celebes (Pätel's collect.), the Gulf of Aniboina 

 (RuMPH and v. Martens), Sorong (Tapparone Canefri), New Caledonia (Frauenfeld). 



According to v. Martens, ■' it is said to be able to live in brackish water and 

 (in the Phillipines) perhaps even in freshwater. F. P. Marratt'^' records it (but this 

 is surely an error) as obtained by the "Argo Expedition" at Abaco (Bahama Islands). 

 Swainson's name Brachidontes, as a sub-genus of Modiola, was altered to Brachy- 

 dontes by P. Fischer, and afterwards by Jukes-Browne' to the generic name 

 Brachyodontes. 



' E. V. Martens, Süss- u. Brackwasser Mollusken d. Indisch. Archipels, p. 87. 



- It is strange that Dunker iProc. Zool. Soc. Lend., 1856, p. 362) in his diagnosis of this species 

 fi-om Cuming's collection says: "testa . . . parum splendida." Reeve, on the contrary, characterizes the 

 same specimens as "shining" (nitente). 



' Probabl}' identical with M. perfragilis, Dunk. 



■" Magaz. de Zoologie éd. p. Guérin-Méneville, II, 1840, pl. 13, "from Kamtschatka" is undoubtedly 

 synonymous with M. glaberrima, Dunk. 



5 Loc. CiL p. 226. 



" HiGGiNS and Marratt, Mollusca of the Argo Expedition to the West Indies, 1876, Liverpool 

 Museum Report, No. 1, 1878, p. 423. 



' Proceed. Malacolog. Soc. London, vol. VI, 1905, pp. 221—23. 



