256 THE voYA(;i<: of h.m.s. challenger. 



Limopsitt caucdluta (iJeeve). 



Pectunculus cancellatus, Reeve, L'uiicli. Icon., vol. i. lig. 39. 



Limopsis woodwardi, A. Adams, Proc. Zool. Soc. Lond., 1S62, p. 231. 



Limopsis pMlippii, A. Adams, op. cit., p. 230. 



Habitat. — Flinders Pas.sage, Station 186, AVednesday Island, Cape York; and Station 

 188, in 28 fathoms (Challenger); Singapore (Reeve); Lizard Island, Torres Strait (Adams). 



After a careful study of the above so-caUed species I cannot Hud any good reasons 

 for their separation. The small difference in form is of little importance, as all the 

 species of this genus appear to l)e more or less variable in this respect. Tlie sculpture 

 of aU three is essentially the same, and the hinge-teeth, about twent5'-two in numl)er, 

 and the ligamental pit are quite similar in all. The inner edge of the valves is smooth 

 and flattened, the extreme outer edge Ijeing minutely crenulated by the external ridges. 

 The epidermis is finely pilose, and in concentric fringes. 



Limopsis bassi, n. sp. (PI. XVIII. figs. 6— 6a). 



Testii Limojisidi canceJlatcB similis, sed major, niagis obliijua ct trausver.sa, dentibus 

 minus numerosis raunita, iutus et extra plus minusve fusco tincta. 



This species has a clathrate exterior like that of Limopsis canveUata of Reeve, but 

 may be distinguished by its more transverse and ol)lique growth, which appears to 1)6 

 constant in the good series of specimens at hand. It is also a larger shell, and, when 

 the thick pilose epidermis is removed, is seen to be stained with a reddish -lirowu tint, 

 except towards the umbones. The hinge -teeth are only aliout fifteen or sixteen in 

 number, or six or seven fewer than in LAmopsis canccUata, and that too, a smaller form. 

 The striated interior and the smooth flattened outer margin are alike in both species, 

 except that the latter in Limopsis bassi is usually tinted with reddish -lu-own. 



Length 22 mm., height 18, diameter 9. 



Habitat. — Station 162, off' East Moncoeur Island, Bass Strait, in 38 fathoms; sand 

 and shells. 



To show the variation in form, I give the following dimensions of another unusually 

 long specimen : — length 20 mm., height 15 J, diameter 8i. 



Limojisis brazievi, Angas. 



Limopisis hrazieri, Anga.«:, Proc. Zool. Soc. Lond., 1S71, I'p. 21, 101. 

 Habitat. — Port Jackson, in 2 to 10 fathoms. 



I have not much to add to Mr. Angas' description of this little species, but nia}- 

 observe that the fine concentric ridees are seen under a strong lens to be somewhat 



