69 165 



thick and convex. The suiTace-sculpture consists of 13 — 14 strong, distinctly pro- 

 minent, rounded radiating ribs wliich bear numerous rather close-set, arched scales, 

 and transverse tubercles. The interstices between the ribs are about as broad as the 

 ribs and have close-set, rough folds and lines of growth. The beaks are situated to- 

 wards the anterior end, they are acute and slope rather suddenly down towards that 

 end, which is rather pointed as compared with the truncated posterior end, towards 

 which the dorsal side descends gradually from the beaks in a straight line. The 

 lunule, which is smooth and oblong, projects a little along the central line. The 

 hinge consists of a single, central, conical, triangular tooth in the right valve, which 

 fits in between two more slender, divergent teeth in the left; the lateral teeth are 

 well developed and equidistant. The hinge-plate between the cardinal and lateral 

 teeth is seen under magnification to be provided with close-set, fine folds and striæ. 

 In the interior the margin is dentate owing to the external ribs projecting there. 



Long. 3 mm., alt. 25 mm., crass. 2 mm. 



Koh Kram, 30 fathoms (3 + ^/s). Between Koh Mesan and Cape Liant, 5—9 

 fathoms, sand (-/s). Between Koh Rin and ClitT Rock, 15 fathoms (-/ä). E. of Koh 

 Chuen, 9—10 fathoms, shells (1). Koh Chuen, 10—15 fathoms (^/a). Koh Chuen, 

 30 fathoms (1 + i/s). S. of Koh Chuen, 30 fathoms, shells (1 + '-'li). Koh Kahdat, 

 1—5 fathoms, sand (1 + ''/a). N. of Koh Kahdat, 4—5 fathoms, coarse sand {'/a). 

 Between Koh Kut and Koh Kahdat, 10 fathoms, shells (1). S. of Koh Kut, 17—20 

 fathoms, mud ('/a). 



Singapore, shallow water ("/a). 



The individuals vary greatly in regard to outline, the position of the unibones, 

 and the sculpture. I am convinced that Card, pidchella does not become much 

 larger than the individuals I have before me, because several of the largest specimens 

 are greatly thickened and solid, i. e. increase in size has ceased, and growth is 

 continued only as regards the thickening of the valves. — Card, pulcbella is most 

 nearly related to Carditella Torresi, Edg. Smith, which is, however, larger, and differs 

 in several essential points from my species. 



Fam. Cyprinidae. 



Trapezium angulatum, Lam. 



CgpHcanUa amjulata, L.^marck, Hist. nat. d. aiiim. s. vert., VI, 1819, p. 28, No. 2. — éd. 2, VI, 1835, p. 



438, No. 2. 



— — - Deshayes, Traité élém. de Conchyliologie, II, p. 18, pi. 24, figs. 10—11 



(C. angiilosa, Lam.). 



— — — Reeve, Concho). Icon.. I, 1843, Cypricardia, Sp. 2. 



Trapezium anijnhitnin, — H. &A. Adams, Genera of ree. Mollusca, II, 1858, p. 439, pi. 109, fig. 5a, b. 



Cypricardia (inyulata, — Hidalgo, Fauna malacol. de I. isl. Filipinas, II, 1003, p. 305, No. 462. 



Cluima oblonga, Linné var., Chemnitz, Conchyl. Cabin., XI, 1795, p. 238, pl. 203, figs. 1993-94. 

 Libitina bicarinala. Schumacher, Essai d'un nouv. système d. habitations d. vers testacés. 1817, p. 1R9. 



pi. 17, fig. 2. 



