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 pallial sinus is short. 
Long. 8 mm., alt. 6 mm., crass. 4°55 mm. 
West of Koh Kut, 30 fathoms, sand and mud (‘/2). 
This new species is most nearly allied to Ch. lionata, Smith, from which it is, 
however, easily dislinguished by its peculiar sculpture. 
Chione (Timoclea) lionata, E. Sm. 
(PI. V, Figs. 8—10). 
Venus (Chione) lionata, Epc. Smirn, Report on the Lamellibranchiata of the Challenger Exped., 1885, 
p. 126, pl. 3, fig. 7. F 
Between Koh Rin and Cliff Rock, 15 fathoms (°/2). Koh Kram, 30 fathoms (?/2). 
Off Koh Kam, 10 fathoms, gravel (‘/2). E. of Cape Liant, 9 fathoms, shells (1/2). 
S. of Koh Samit, 20 fathoms, mud (‘/2). S. of Koh Chuen, 30 fathoms, shells (15). 
Between Koh Chuen and Koh Chang, 15 fathoms, mud (°*/2). S. of Koh Kahdat, 
8—10 fathoms, mud (/2). Between Koh Kut and Koh Kahdat, 10 fathoms, shells (17). 
S. of Koh Kut, 17—20 fathoms, mud (*/2). W. of Koh Kut, 15 fathoms, mud (7/2). 
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 Epa. Smirn’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 Smrru’s figure is not very good I have 
here given a new figure. 
Chione (Antigona) lamellaris, Schumacher. 
Antigona lamellaris, ScHuMACHER, Essai d'un nouv. systeme d. habitat. d. vers testacés, 1817, p. 155, pl. 
14, fig. 2. 
Venus = = Marini u. CuEmnirz, Conchyl. Cabin., XI, 1 Abth., p. 142, pl.8, figs. 10—11, 
