112 COLLECTIONS FKOM MELANESIA. 



a transparent white colour, and not pale olive-green like the rest 

 of fche surface. At the anterior end a few oblique lines, commencing 

 at the ridge which borders the lunule, fall across the concentric 

 sculpture, but are only noticeable in certain lights. The dorsal 

 margin is very faintly arcuate in front and scarcely descending, a 

 trifle more oblique behind, and rectilinear except near the extremity, 

 where there is a very feeble sinuation. The lower outline is broadly 

 arcuate, considerably upcurvingin front, and at its junction with the 

 dorsal edge forms an obtuse or rounded angle : at the posterior 

 end it ascends more gently (the curve being indistinctly interrupted 

 by a very faint prominence which defines the portion of the surface 

 upon which the concentric ridges are finer than elsewhere), pro- 

 ducing with the dorsal slope a sharpish rostrate end. The umbones 

 are rather large and prominent, coarsely concentrically sculptured, 

 situated a little posterior to the centre, and incline somewhat 

 towards the hinder side. The dorsal areas are distinctly defined by 

 elevated margins, and the posterior is broader than the anterior or 

 lunule. Teeth about 43 in number, whereof about 16 are on 

 the posterior side, and the rest in front. The interior of the valves 

 is transparent milky white, and the margin is acute and smooth. 

 The pallial sinus is deep, narrow, and rounded at the end. Length 

 17g millim., height 9§, diameter 7. 



Hah. Port Darwin, <^-12 fins., mud and sand bottom. 



This species is very closely related to L. confusa, Hanley. It is, 

 however, thinner, not so equilateral, more coarsely sculptured, has 

 more prominent umbones, and the margin of the valves is not 

 minutely crenulated within. 



62. Malleus legumen. 



Reeve, Conch. Icon. fig. 2. 



Hah. Philippine Islands {Cuming); Port Curtis (Coppinger). 



The interior of this species is waxy white, except the upper part 

 of the nacreous portion beneath the ligament, where there is a large 

 dark purplish spot. The non-nacreous portion exhibits a raised sub- 

 central ridge extending from the margin of the pearly lining nearly 

 to the lower extremity. 



63. Avicula lata. 



Gray, 1845, Appendix to Eyre's Central Australia, p. 435, pi. 6. fig. 1 ; 



Reeve, C'tmth. Icon. fig. 5. 

 Avicula serrulata, DunJcer, Zeitsehr. f. Maldk. 1848, p. 178 ; Conch.- 



Cab. ed. 2. p. 18, pi. 5. figs. 1, 2. 



Hot,. West Island, Torres Straits, in 7 fms., sand (Coppinger); 

 Port Essington (J. B. Jukes in Brit. Mus.); Raine's Island, Torres 

 Straits ( Lieut, luce, 11. A., in Mus. Cuming) ; Moluccas (BunTcer). 



R( eve and Dunkcr appear to have been unaware that this species 

 was both figured and described by Gray. Apparently, as a rule, it 

 is longer than either of the specimens figured in the ' Conch. Icon.' or 



