36^ 



A NEW SPECIES OF MODlOLA FROM MALACCA. 



By EDGAR A. SMITH, I.S.O. 



(Read before the Society, September 9, 1903.) 



The species about to be described was obtained by Mr. Richard 

 Evans in the Tale Nawi in Lower Siam. This semi-lake is probably 

 brackish water, being almost enclosed from the sea, and having several 

 rivers and streams running into it. 



Modiola evansi, n. sp. 



Testa parva, tenuis, antice angusia, lutescens, postice dilatata, viridts, 



lineis radiantibus saturatioribiis picta, infra umbones sidcis circiter 



qiiatuor curvatis sculpta et striis paiicis ab umbonibus ad marginem 



vefttralem postice ornata, incrementi lineis tenuissimis sculpta; margo 



dorsi rectus, ventralis incurvatus ; pagitia interna bicolorata, supra 



nigropurpurascens, infra albida, iridescens, ad marginuni antice et 



portice crenulata, in medio Icevis; umbones pallidi, haud terminales, 



fere contigui. Longit. 14 mm., alt. 7, diam. 4^. 



This pretty species is distinguished by its small size, its form and 



colouration. The few sulci at the anterior end are coarser than those 



down the umbonal angle which reach the ventral margin rather 



behind the middle of it. The anterior end of the valves is denticulate 



at the margin, the denticles being very fine towards the umbo. The 



dark radiating lines on the posterior part of the shell are very slightly 



raised and thus produce a faintly crenulated margin which is most 



evident within the valves. 



Dr. W. G. Ridewood has incidentally referred to this shell in his 

 memoir on Lamellibranch gill-structure in the Philosophical Trans- 

 actions, 1903, series B, vol. 195, p. 203. 



