69 165 
thick and convex. The surface-sculpture consists of 13—14 strong, distinctly pro- 
minent, rounded radiating ribs which 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 thal 
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 striz. 
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 + 4/2). Between Koh Mesan and Cape Liant, 5—9 
fathoms, sand (?/2). Between Koh Rin and Cliff Rock, 15 fathoms (?/2). E. of Koh 
Chuen, 9—10 fathoms, shells (1). Koh Chuen, 10—15 fathoms (*/2). Koh Chuen, 
30 fathoms (1 + 4/2). S. of Koh Chuen, 30 fathoms, shells (1 + !°/2). Koh Kahdat, 
1—5 fathoms, sand (1 + °/2). N. of Koh Kahdat, 4—5 fathoms, coarse sand (1/2). 
Between Koh Kut and Koh Kahdat, 10 fathoms, shells (1). S. of Koh Kut, 17—20 
fathoms, mud (‘/2). 
Singapore, shaliow water (°/:). 
The individuals vary greatly in regard to outline, the position of the umbones, 
and the sculpture. I am convinced that Card. pulchella 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. pulchella 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. 
Cypricardia angulata, Lamarck, Hist. nat. d. anim. s. vert., VI, 1819, p. 28, No. 2. — éd. 2, VI, 1835, p 
438, No. 2. 
-- _ — Drsuayes, Traité élém. de Conchyliologie, IH, p. 18, pl. 24, figs. 10—11 
(C. angulosa, Lam.). 
= = — REEVE, Conchol. icon.. I, 18438, Cypricardia, Sp. 2. 
Trapezium angulatum,  — H. & A. Apams, Genera of rec. Mollusca, II, 1858, p. 439, pl. 109, fig. 5a, b. 
Cypricardia angulata, — HipauGo, Fauna malacol. de |. isl. Filipinas, II, 1903, p. 365, No. 462. 
Chama oblonga, LINN var., CHEMNITZ, Conchyl. Cabin., XI, 1795, p. 238, pl. 203, figs. 1993—94. 
Libitina bicarinata, ScHuMACHER, Essai d’un nouy. systéme d. habitations d. vers testacés, 1817, p. 169, 
pl. 17, fig. 2. 
