266 170 



E. of Cape Liant, 9 fathoms, shells (5). Gulf of Rayong, 7 — 10 fathoms, sand 

 and mud (2). S. of Koh Saniit, 14—20 fathoms, mud (6). S. of Koh Tulu, 10 

 fathoms, mud (2). W. of Koh Chang, 20 fathoms, mud (Ws). N. of Koh Kahdat, 

 4—5 fathoms, coarse sand (1). Koh Kahdat, 1 — 5 fathoms, sand (1). Between Koh 

 Kahdat and Koh Kut, 6 — 10 fathoms, mud mixed with sand (■''/2). Koh Mak, sandy 

 coast (^/s). S. of Koh Mak, 5—6 fathoms (2). W. of Koh Kong, 10—15 fathoms (1). 



Long. 8 — 24 mm. 



Distribution: — Singapore, Strait of Malacca, Mergui Archip., Andamans, off 

 Port Blair, Andaman Isls., 100 fathoms (Edg. Smith), Gulf of Manaar. — Poulo 

 Condor, Philippines, Formosa, Strait of Macassar, New Guinea, Torres Str., Mast 

 Head Reef (Queensland), Port Essinglon, Dampier'sLand (NW. Australia), NE. Australia. 



The specimens, for the most part, are thick-valved and vary greatly in form, 

 but quite thin-valved specimens also occur; thus, for example (from Singapore) a 

 left valve of the following dimensions:- long. 19 mm., alt. 7 mm., crass. 4 mm.; 

 it is very thin-valved, and without a trace of the denticulation upon the dorsal and 

 ventral margins characteristic of the species; it greatly resembles Edg. Smith's 

 species C. Macgillivrayi, and like the latter it has a shallow depression down the 

 middle (which C. crassa also very frequently has); the hinge characters are also less 

 pronounced than in the thick-valved specimens of C. crassa of the same size, from 

 which it appears to differ greatly, but it is, in reality, only an unthickened individual. 



Corbula (Aloidis) tunicata, Hinds. 



Corbula tunicata, Hinds, Proc. Zool. Soc. London, 1843, p. 5.5. 



— — — Reeve, Conchol. icon., II, Corbula, Sp. 5. 



— — — Zoology of the voyage of "Sulphur," Mollusca, p. fiS, No. 281, pi. 20, figs. 4 — .'5. 



— — — Edg. Smith, Lamellibianchiata of the Challenger Exped.. p. 29. 



— — — Pritchard and Gatliff, Proc. Roj'. Soc. Victoria, vol. 16, 190;^, p. 101. 



— scaphoides, — Proc. Zool. Soc. London, 1843, p. 5(). 



— — — Reeve, Conchol. icon., 11, Corbula, Sp. 24. 



— — — Edg. Smith, Lamellibranchiata of the Challenger Exped., p. 32, pi. 7, fig. 3. 



— — — Pritchard and Gatliff, Proc. Roy. Soc. Victoria, vol. 16, 1903, p. 101, 



NW. of Koh si Chang, 10 fathoms, mud (1). Gulf of Rayong, 7—10 fathoms, 

 mud ('/ä). Sound of Koh Chang, 5 fathoms, soft clay ('/a). West coast of Koh 

 Chang, 10 fathoms, mud (V2). S. of Koh Bidang, 9 fathoms, mud (1). S. of Koh 

 Mak, 5 — 6 fathoms (4). Between Koh Kahdat and Koh Kut, 6-10 fathoms, mud 

 mixed with sand ("/a). N. of Koh Kut, 10 fathoms, mud (-/a). W. of Koh Kut, 

 15 fathoms, mud (3). 



Long. 7 — 25 mm. (long. 25 mm., alt. 17 mm., crass. 14 mm.). 



Distribution: — {t. = tunicata, Hinds; s. = scaplwides, Hinds). Singapore (s.), 

 Mergui Archip. (t.), Ceylon (s.), Cape of Good Hope (/.). — Philippines (/. s.), China 

 Sea (t.), Hong Kong Harbour (s.), Amboina (/.), Strait of Macassar (f.), Arafura 

 Sea (/. ), Torres Strait (t.s.), Cape York (s.). Port Jackson, Sydney (t. s.), Mast Head 

 Reef, Queensland (s.), Port Molle, Queensland (/. s.), Victoria (/. s.). Port Darwin, 

 NW. Australia (/.), Tasmania (s.). 



