BAHNACT.EH FROM MAGNETIC lAI.AND, NOKTIf QIM^IENSLAND. 12:i 
Family CHTHAMALID.F. 
Geims CHTHAMALUS, Ranzani, 1817. 
CHTHAMALUS sp. 
There are seven examples on specimen P. 2026, all showing only the base of 
the shell, and one has the inner surface of the opercular valves exposed. The walls 
of the shell are tliick, although aft(ir due allowance has been made for the fact that 
they have been worn down by erosion, they are probably no thicker than in the 
Australasian species C. antennatus Darwin (1854, p. 460, pi. xviii., fig. 2). They may 
even belong to that species, but the apparent toothed edges of the radii, and the 
sinuous basal margin of the scutum, does not allow one to be at all confident. Largest 
shell with a rostro-carinal lengtli of 7 mm. 
Genus OCTOMERIS, G. B. Sowerby, 1825. 
So far this genus is known only by 0. angiilosa G. B. Sowerby (1825, p. 244, 
pi. xii. Suppl.) from South Africa, by 0. hrunnea Darwin (1854, p. 484, pi. xx., 
figs, 3a, b; Nilsson-Cantell, 1021, }>. 200, text-hgs 58, 50, pi. iii, fig. 7 ; 1926, p. 1 ; 
1030, p. 10) from the Philippine Archipelago, Sumatra, Java, and Pisang Island, 
S.W, of New Guinea, and by 0. interniedia Nilsson-Cantell (1021, p. 303, text-figs. 
60-61, iii. fig. 8 ; 1026, p. 1) from Java. 
OCTOMERIS CRASS A sp. n. 
(Text-figs. 1, 2). 
Diagnosis . — Shell brownish coloured, depressed, closely but not so regularly 
ribbed radially as in 0. hrunnm, with numerous interlocking ribs along the natural 
edges ; walls extremely thick. 
OCTOMERTS CRASSA n. Sp. 
Fig. 1.— Shell, viewed from the base. 
Fig. 2— Lateral and carino-lateral compartments, attached, (a) Outer view ; (5) inner view, 
