140 44 



Gulf of Rayong, 7 — 10 fathoms, mud ('/s). Koh Kram, 30 fathoms ('/-■). Between 

 Koh Mesan and Cape Liant, 5 — 9 fathoms (^/a). Koh Kalidal, 1—5 fathoms, sand (-/j). 



Long. 4 — 13 mm. 



Distribution: — Port Lincoln, South Australia (Cuming), Sullivan Isl., 

 Mergui Archip. (v. Martens). 



Dunker and Reeve give the size of the specimens in Cuming's collection as 

 4 mm.; from the Gulf of Siam there are specimens measuring as much as 13 mm. 

 Reeve's figure (very badly reproduced in Clessin's Monograph in "Martini & 

 Chemnitz") is not good in all points, hence I have given a new figure here. As 

 all the specimens from the Gulf of Siam were taken dead, I have not been able 

 to verify Dunker's statement: "Pagina interna margaritacea." 



Modiolaria miranda, Edg. Smith. 



Modiolaria miranda, Edg. Smith, Rep. Zoolog. Collect, made during the voyage of H. M. S. "Alert." 1884, 

 p. 1(»8. pi. 7, fig. N. 



Common (from 16 different localities) between Koh Rin and Koh Kut, 1 — 30 

 fathoms, stones, shells, gravel and mud. 



Long. 1 — 7 mm. 



Distribution: — Dundas Straits. 



Some of the specimens were taken from among the spines of Slephanocidaris 

 bispinosa, Lam., from a depth of 30 fathoms. 



Modiolaria (Gregariella) opifex, Philippi (non Say). 



Modiola opifex (Say'?), PiiiLiri'i, Abbild, u. Beschreib, neuer od. wenig gekannt. Conchyl., Ill, 1851, 

 Modiola, p.21 (7), pl. 11, fig. 7. 

 — — Say, Reeve, Conchol. icon., X, Modiola, Sp. 39. 



Lilhophaga opifex, Say, Dunkeu in Martini u. Chemnitz, Conchj'l. Cabin., VIII, 3 .'\btli. ,\, p. 211, pl. (j, 



flg. l(i. 

 Litliodomus splendidus, Reeve (non Dunker), Reeve, Conchol. icon., X. Lithodoimis, Sp. 31. 



Between Koh Mesan and Koh Chuen, 25—38 fathoms, stones (7). Between 

 Koh Mesan and Cape Liant, 5—9 fathoms (''l). 



Long. 9—15 mm. 



Distribution: — Sydney (Cuming). — Brazil (Henr. Krover; Desterro, Fr. 

 Müller; Rio Janeiro, Cuming). 



In all the specimens from the Gulf of Siam the most posterior, flattened part 

 of the valves, limited by ridges set with stiff epidermal bristles, was covered with 

 adherent grains of sand; this gives the animals, which live buried in the sand, 

 a great resemblance to their surroundings. Modiola difficilis, Deshayes, ' appears to 

 me to resemble more particularly a worn specimen of the present species. 



> Mollusques de I'ile de la Reunion (Bourbon), 18()3, p. 23, pl. 3, figs. 22—24, 



