149 245 



whole of the middle portion, numerous close-set, fine, regularly-arranged ribs, which 

 fork towards the ventral margin; then, towards the posterior end, 6 — 9 strong 

 ribs occur, which are less broad than the interstices between them; where these 

 posterior radiating ribs meet the concentric ribs, the bead-like granules which occur 

 upon the rest of the shell become strong scales. On the somewhat elongated lunule 

 only slightly granulated, radiating ribs are found ; the large oblong area is quite 

 smooth, without any ribs. The interior of the valves is white and somewhat 

 glossy. There are three teeth in each valve, the central one in the left valve and 

 the central and posterior in the right are tripartite at the top; the posterior tooth 

 in the left valve is only slightly developed. The inner margin is finely crenulated 

 all the way round, but most strongly at the ventral margin, and most finely and 

 closely at the lunule-margin. The palliai sinus is short. 



Long. 8 mm., alt. 6 mm., crass. 45 mm. 



West of Koh Kut, 30 fathoms, sand and mud ("/s). 



This new species is most nearly allied to Ch. lionata. Smith, from which it is, 

 however, easily distinguished by its peculiar sculpture. 



Chione (Timoclea) lionata, E. Sm. 



(PI. V, Figs. 8— l(t). 



I'eni/s [Chione] lionata, Edg. Smith, Report on the Lamellibranchiata of the Challenger Exped., 1885, 

 p. V2G, pi. 3, fig. 7. 



Between Koh Rin and Cliff Rock, 15 fathoms f/s). Koh Kram, 30 fathoms (a/a). 

 Off Koh Kam, 10 fathoms, gravel ('/a). E. of Cape Liant, 9 fathoms, shells (Va). 

 S. of Koh Samit, 20 fathoms, mud ('/a). S. of Koh Chuen, 30 fathoms, shells (15). 

 Between Koh Chuen and Koh Chang, 15 fathoms, mud (-'/a). S. of Koh Kahdat, 

 8—10 fathoms, mud (^/a). Between Koh Kut and Koh Kahdat, 10 fathoms, shells (17). 

 S. of Koh Kut, 17—20 fathoms, mud (*/a). W. of Koh Kut, 15 fathoms, mud (-/a). 



Long. 8 mm., alt. 65 mm., crass. 5 mm. 



Distribution: — Singapore, shallow water (Danish Exp. to Siam). — Amboina, 

 S. of New Guinea (Challenger). 



I have compared my specimens with Edg. Smith's original types in the 

 British Museum ; they exactly agree with his specimen from Amboina (which he 

 regards as a variety), while his specimens from New Guinea are somewhat different. 

 Judging from the large quantity of material at hand from the Gulf of Siam it 

 appears, however, that the species varies considerably. As may be seen from the 

 measurements given above, the specimens from the Gulf of Siam are larger than 

 Smith's from the Challenger Expedition. As Smith's figure is not very good I have 

 here given a new figure. 



Chione (Antigona) lamellaris, Schumacher. 



Antigona lamellaris, Schumachek, Essai dun nouv. systime d. habitat, d. vers testaces, 1817, p. 155, pi. 



14, fig. 2. 

 Venus — — MARTiNiu.CHi;MMTZ,Conchyl.Cabin.,XI,l Abth., p.l42. pl.8, figs. 10— 11. 



