123 219 
indistinctly in his figure; and Lamarck observes regarding glabrata: “natibus um- 
bonibusque glabratis,’ but this slight difference which is probably intended to 
be the chief distinguishing point (the striation of the rest of the shell being no 
doubt almost similar in both the species), is confined to a matter of taste. On 
examining the figures, e.g. of glabrata by Apams (loc. cit.) and of striata by REEVE 
(sp. 10), it will be seen that the sculpture is almost similar, and that the form 
differs but slightly; but the material of M. glabrata at my disposal shows that the 
outline varies highly — from a high triangle (long. 27 mm., alt. 23 mm.) to an oblong- 
ovate form (long. 24 mm., alt. 18 mm.). — It is desirable that these two forms should 
be compared with each other, and especially that striata should be more accurately 
characterized. In glabrata the regularly-arranged concentric striation begins gene- 
rally when the shell has reached a height of about 8—12 mm., but it may often 
be traced before this. 
Davila crassula, Desh. 
Mesodesma crassula, DesHayers, Proc. Zool. Soc. London, XXII, 1854, p. 336, No. 87. 
_ -- Reeve, Conchol. icon., VII, Mesodesma, Sp. 26. 
Davila — H. & A. Apams, Genera of rec. Mollusca, pl. 106, fig. 6. 
Mesodesma = = HrpavGo, Fauna malacol. de 1. isl. Filipinas, II, p. 66, fig. 135. 
Koh Kahdat, 1—5 fathoms, sand (3). On the coast of Koh Kahdat (°*/:). 
Long. 8—18 mm. 
Distribution: — Elphinstone Isl. (Mergui Archip., v. Martens), Philippines. 
Ervilia bisculpta, Gould. 
(Pl. IV, Figs. 14—16). 
Ervilia bisculpta, GouLp, Proceed. Boston Soc. Nat. Hist., VIII, 1861—62, p. 28. — Otia Conchol., p. 166. 
— _ — Epc. SmirH, Report on the Lamellibranchiata of the Challenger Exped., p. 80. 
Ervillia — — Pivspry, Catal. Mar. Moll. Japan, 1895, p. 118. 
Ervilia _- — Hep.ey, Proc. Linn. Soc. New South Wales, vol. 31, 1906, p. 479, pl. 36, fig. 8. 
— australis, ANGAS, Proc. Zool. Soc. London, 1877, p. 175, pl. 26, fig. 21. 
— incolor, DesHayes, MSS. in Brit. Mus. 
Corbula isomeros, Hinps, MSS. in Cuming’s Collection, Brit. Mus. 
Koh Kram, 30 fathoms (°/:). N. of Koh Kam, 5 fathoms, gravel (1). Koh 
Mesan, 15 fathoms, stones (3). Between Koh Mesan and Cape Liant, 5—9 fathoms, 
sand (42). W. of Koh Chuen, 5 fathoms, gravel (1). North end of Koh Chang, 1—2 
fathoms, old coral blocks (*/2). Koh Kahdat (6). Between Koh Kut and Koh Kahdat, 
10 fathoms, shells (1/2). W. of Koh Kut, 15 fathoms, mud (4). 
Long. 15—5 mm. 
Distribution:— Singapore (shallow water, Sy.Gap). Durban (BurNup). — 
Philippines, Japan, Mast Head Reef (Queensland), Port Jackson (Sydney), Sand- 
wich Isls. 
ANGAS’s figure of E. australis (Proc. Zool. Soc. London, 1877) corresponds badly 
with his diagnosis of the same species, and it is upon EpG. Smitu’s authority alone 
that I give it as a synonym of E. bisculpta. 
28° 
