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

;MOLLUSCA. 81distances, eleven in the front one, and one on each side of the intermediatevalves. The interior is pale blnish, the latter valves havingan olive-brown stain radiating from the vertex behind on each side,and the two terminal valves have marks of the same colour near themiddle.The girdle is covered with altcrnateh" pinkish and dark greyishpatches of fine oval compressed imbricating scales, of which thosetowards the outer margin are much smaller than those near thevalves.Length without girdle 21 millim. ; diameter of fifth central 2)late 8.Hab. Port Jackson {Co2)phu/er).This species is closely allied to C. avtiquus, but is diff'erently andmore finely sculptured and the scales on the mantle are larger.112. Chiton (Acanthopleura) spiniger.Chiton spiniger, Sowerhy, Conch. III. fig. 08; Reeve, Conch. Icon.fig. 7o; Gray, 1857, Giiide Moll. Brit. Mtis. p. 184 (Maugeria)|; Ball,Bull. U.S. Nat. Mus. i. p. 80 (Acanthopleura).Chiton granatus, Reeve, Condi. Icon. fig. 24.Chiton macgillivrayi, A. Adams, Proc. Zool. Sac. 1855, p. 120.Acanthopleura glareosa, MS. in Mus. Cuming.Maugeria owenii. Gray, (ruide Moll. p. 184.? Chiton borbouicus, Deshayes, Moll, de Reunion, p. 37, pi. v. figs.12,13.? Chiton piceus, Reeve {non Gmelin), Conch. Icon. fig. 70.= Chiton obesus, Shidtleworth, Bern. Mittheil. 1853, p. 79.? Chiton cunniughamii, Reeve, I. c. fig. 18.Hcih. Philippine Islands (Cuminr/) ; Port Essington (Jnl-es);Port Molle and Clairmont and Bird Islands (Cojipinr/er) ; Piji, forC. macgillivrayi.The specific difference, if it exist, between the West-IndianC. piceus of Gmelin and C. spiniger is not very apparent. On closecomparison I find that the central valves of the former are as a rulemore peaked posteriorly, the colour within is bluish, with a conspicuousmark, almost black, at the jugal sinus. On separatingthese valves the greatest diameter is found to exist at the posteriormargin, the lamina3 of insertion narrowing in front. On the contrary,in C. spiniger the greatest width is across the lamina; anteriorto the lateral notch. There appears to be very little difference inthe insertion-teeth of the first and last valves of these two forms.113. Chiton (Acanthopleura) incanus.Chiton incanus, Gould, Proc. Bost. Soc. Nat. Hist. 1846, vol. ii.p. 145'; Otia,'' pp. 6, 248 (Maugeria) ;Wilkes's Explor. Krped.p. 315, figs. 432, 432 «.Hab. New South Wales (Gould); Port Jackson (Coppinger)Stewart Island, New Zealand (C. Traill, Esq., in Brit. Mus.).Externally this species bears considerable resemblance to 0. sjnniger,both as regards the sculpture of the valves and the characterG