Report on the zoological collections made in the Indo-Pacific Ocean ...

'MOLLUSCA. 0365. Rissoina curtisi. (Plaie Y. fig. M.)Shell elongate, thick, white, very coarsely cancellated. Numberof whorls unknown, the apex being broken off ; the remaining fourare obliquely sloping at the upper part, and, with the exception ofthe last, biangulated at the sides, the angles being caused by theprominence of two spiral liraj upon the longitudinal costse. A thirdlira is seen at the base of the whorls at the suture. The costoe areabout fourteen on a whorl, about as thick as the transverse ridges,and nodulous at the points of intersection. The body-whorl hasfive spiral lir?e, the lowermost being separated from those above bya broad smooth furrow, in which the costas are almost obsolete.Aperture obliquely subovate, rather widely channelled in front.Columella oblique, covered with a thin callosity, which at the baseforms the sinistral side of the canal. Labrum much thickened exteriorly,acute at the margin, and (viewed laterally) is produced tothe left at the front part.Probable length about 7 millira. ; actual length of remaining fourwhorls 5| millim., width 2g.Hah. Port Curtis, 7 fms.This species might be considered a dwarfed, strongly cancellatedform of 11. clathrata ; it is less slender, has fewer and stouter costse,and the spiral lirte are also thicker and two in number upon theupper whorls exclusive of those at the suture, whilst in the speciesreferred to there are three. The outer lip is much thickened andthe aperture rather more contracted.66. Cerithium morus.Lamarck, Am'ni. suits Vert, ed, 2, vol. ix. p. 302 ; Kiciier, Coq. Viv.p. 52, pi. 15. fig. 1 ; Soiverby, Thes. Conch, figs. 159-161 ; id. Conch.Icon. tig. 42.Var. ^ Cerithium moniliferum, Dvfresne, Kiener, Coq. Viv. p. 49,pi. 16. fig. 3; Sowerhy, Thes. figs. 163, 165 ; id. Conch. Ic. fig. 20.Var. = Cerithium carbonarium, Sowerhy (non Philippi), Conch. Icon.fig. 59.Uab. Philippine Islands (Cttminr/) ; Samoa Islands (Hev. S. J.Whitmee in Brit. Mus.) ; Port Jackson, 7 fms. ; Friday Island,Roko Island, Endeavour Strait, and West Island, Prince of WalesChannel, Torres Straits (Coj>2ringer) ; Dungeness Island, TorresStraits (Brazier) ; Hall Sound, New Guinea {Brazier).The small group of species to which C. moms belongs, includingC. tuherculatum of Linnaeus as defined by Hanley (' Ipsa Linna^iConchylia,' p. 276, pi. iv, fig. 4), C lemniscatum, C. breve, and C.variegatam, Quoy and Gaimard, O. petrosum and 0. riigosum ofWood (non Lamarck) =G.patiens, Bayle, C. moniliferurii,~K\ei\cr, G.gemma, C. purpurascens, C. bifasciatum, C. pupa, and C. nigrofasciatumof Sowerby, is very perplexing, owing to the great similarityin sculpture of the various species.1. C. tuherculatum, to which I unite as varieties C. variegatam,