123 219 



indistinctly in his figure; and Lamarck observes regarding glabrala: "nalibiis um- 

 bonibusque glabratis," but this slight ditïerence 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 Adams (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 oi 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, Deshayes, Proc. Zool. Soc. London, XXII, 1854, p. 336, No. 87. 



— — — Reeve, Conchol. icon., V!II, Mesodesma, Sp. 26. 



Davila — — H. & A. Adam.s, Genera of rec. Mollusca, pi. 106, fig. 6. 



Mesodesma — — Hidalgo, Fauna malacol. de 1. isl. Filipinas, II, p. 66, fig. 13.5. 



Koli Kahdat, 1—5 fathoms, sand (3). On the coast of Koh Kahdat (^h). 



Long. 8 — 18 mm. 



Distribution: — Elphinstone Isl. (Mergui Archip., v. Martens), Philippines. 



Ervilia bisculpta, Gould. 



(PI. I\', Figs. 14-16). 



EruilUt biscnlpla, Goui.d, Proceed. Boston Soc. Nat. Hist., VIII, 1861 — 62, p. 28. - Olia Conchol., p. 166. 



— — — Edg. Smith, Report on the Laniellibranchiata of the Challenger Exped., p. 80. 

 Ervillia — — Pilsbry, Catal. Mar. Moll. Japan, 1895, p. 118. 



Ervilia — — Hedley, Proc. Linn. Soc. New South Wales, vol. 31, 1906, p. 47'J, pi. 36, fig. 8. 



— australis, Angas, Proc. Zool. Soc. London, 1877, p. 175, pi. 26, flg. 21. 



— incolor, Deshayes, MSS. in Brit. Mus. 



Corbiila isomeros, Hinds, MSS. in Cuming's Collection, Brit. Mus. 



Koh Kram, 30 fathoms (/a). 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 ('/s). Koh Kahdat (6). Between Koh Kut and Koh Kahdat, 

 10 fathoms, shells ('/a). W. of Koh Kut, 15 fathoms, mud (4). 



Long. IS — 5 mm. 



Distribution: — Singapore (shallow water, Sv. Gad). Durban (Burnup). — 

 Philippines, Japan, Mast Head Reef (Queensland), Port Jackson (Sydney), Sand- 

 wich Isis. 



Angas's figure of E. australis (Proc. Zool. Soc. London, 1877) corresponds badly 

 with his diagnosis of the same species, and it is upon Edg. Smith's authority alone 

 that I give it as a synonym of E. bisculpta. 



28* 



