171 267 



I cannot find sufficient reason for separating the two forms funicala and 

 scaphoides as distinct species, the differences are entirely individual. Among the 

 rather large quantity of material which I have at my disposal, are several transitional 

 forms. The vivid coloration which Hinds has given in his figure of tiinicata in 

 the report of the "Sulphur" Mollusca, was not found by me in any of the indi- 

 viduals I have had for examination. 



Corbula (Aloidis) erythrodon, Lam. 



Corbula erythrodon, Lamarck, Hist. nat. d. anim. s. vert., V, 1818, p. 49(j. No. 3. ~ éd. 2, VI. p. 138, No. 3. 



— — — Reeve, Conchol. icon., II, Corbula, Sp. 4. 



— — — LiscHKE, Japan. Meeres-Conchj'l., I, p. 136. 



E. of Cape Liant, 9 fathoms, shells (Vs). N. of Koh Kam, 5 fathoms, gravel (2). 

 Between Koh Riot and Koh Mesan, 3—5 fathoms, sand (1). Between Koh Mesan 

 and Cape Liant, 9 fathoms (1). Koh Kalidat, 1 — 5 fathoms, sand (2 -|- *;2). Between 

 Koh Kut and Koh Kahdat, 10 fathoms, shells (Vs). 



Long. 7 — 20 mm. 



Distribution: — Poulo Condor, China, Japan, New Zealand. 



Corbula pallida, Hinds (recorded from Singapore and the Nicobars), is certainly 

 synonymous with the present species. 



Corbula lineata n. sp. 



(PI. V, Figs. 23—24). 

 This species is oblong-triangular in form, somewhat inequivalve (the right 

 valve being somewhat larger than the left), moderately convex, the valves thick and 

 solid, and whitish in colour with slight indication of pale red. The umbo is 

 situated at about the middle, often nearer to the front end. The apices of the 

 umbones are placed close together and they curve over towards the front. From 

 the umbo a sharp keel extends over each valve down towards the posterior ex- 

 tremity, which is prolonged in a rostrum-like manner. The dorsal margin slopes 

 gradually down towards the front end, from whence it is continued in a curve 

 down to the straight ventral margin. Towards the pointed posterior end the dorsal 

 margin slopes in a straight line. In both valves, when the animal has reached a 

 certain size, the ventral margins turn back and grow inwards towards each other. 

 The portion of the posterior end which is bounded by the two keels forms an 

 oval; towards the central line (the opening between the valves) of this oval there 

 occurs on each side a smaller keel, by which another oblong oval is formed. 

 The surface of the valves is covered with close-set, concentric, raised thread-like 

 lines, the interstices between which are finely striped transversely with close-set 

 radiating lines. The interior of the valves is white, the muscle impressions and 

 the palliai line are yellow; a narrow depression extends from the umbonal region 

 down towards the ventral margin. The solitary cardinal tooth in the right valve 

 is large, strong and curved upwards; it fits into a corresponding pit in the left 

 valve, behind which there is a large denticle supporting the ligament. 



34* 



