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

MOLLUSCA. 79arciiate. Last valve of a narrow acutely elliptic form, with themucro probably near the centre. Interior of the plates greenishblue, stained dark brown in the middle. Lamina of insertion in thefroi]t plate with about ten notches at unequal distances, leavingdifferent-sized teeth between them, which are striated on both sides,but more strongly externally, their edges being sharp, but notsmooth. The central plates have a single minute notcli on eachside, the insertion-lamina being comparatively smooth on the uppersurface and marked with a small brown spot on each side againstthe edge of the valve. Tail-plate much thickened within along theposterior edge, which is roughened by fine cross stria^, there beingno prominent teeth, and of course no notches. Mantle-margincovered with small subimbricating oval granules. Length withoutmargin 10 millim. ; width of fourth plate 9.Hab. Port Curtis (Cojypiiir/e)-).The granules of the surface have an irregular concentric disposition,following to some extent the lines of growth.109. Chiton (Ischnochiton ?) adelaidensis.Reeve, Conch. Icon. fig. 123.Uah. Port Molle, Queensland {Coppinfjer) ; Port Adelaide {Reeve).The entire surface of this species is minutely granoscly reticulated,the front valve, the lateral areas of the narrow central valves, andthe hinder area of the posterior are in addition somewhat irregularlyradiately sulcate. The prevailing colour is pale greenish, streakedand dotted with red, the posterior margin of the valves being palerthan the general tone of the shell, and conspicuously spotted withthe same red colour. The grains of the mantle are smooth, arrangedin alternate greenish and reddish patches, and individually have adark spot generally on the outer side, which is only seen undera lens ; those near the valves are considerably smaller than thosesituated towards the edge of the girdle. Having parted the valvesof one of the specimens I find the front one has the margin ofinsertion divided into seventeen unequal, squarely cut, slightlycrinkled, sharp-edged teeth, of which the two outer on each side arethe largest. The sixteen slits between the teeth are very small andshallow. The second, third, fourth, fifth, and sixth valves haveon each side a single very small narrow central notch, from which agroove or depression runs to the apex of each valve ; the seventh isprobably abnormal, having a single notch on the right side and twoon the left, and the terminal valve has nineteen similar slits.110. Chiton (CallistocMton) antiquus.Chiton antiquus, Heeve, Conch. Icon. fig. 1G9.Callistochiton sarcophagus, Carpenter, MS. in Coll. Cuming.Hab. Australia (lleeve) ; Port Molle, Queensland {Coppinger);Port Jackson, rare (Anr/as).Reeve's figure of this species is much enlarged, the type shell