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

490 COLLECTIONS FROM THE WESTERN INDIAN OCEAN.glossy, convex, non-peri)endicular with the axis of the shell ; therest granosely finely costate and transversely lirate, slightly convexat the sides, Costae about eighteen in number on a whorl, hardlyas broad as the interstices. Line finer than the ribs, six on theupper whorls and about twenty on the last. Aperture small, narrow,terminating anteriorly in a short, oblique, recurved canal.Columella covered with a callus bearing two small tubercles justbelow the middle. Labrum externally thickened with a broadishvarix, faintly siiiuated above near the suture, armed within withseven strongish lirse. Length 5 millim., diam. 1|; aperture 1| long,^ broad.Etoile Island, Amirantes, in 13 fms.There is a little group of species with which that now describedshould be placed, and which does not quite come under any one ofthe as yet named subgenera of Pleurotoma. They are small shellswith cancellated sculpture, having smooth apical whorls, an indistinctlabral sinus, and lirae or denticles within the outer lip.Columbella monilifera, Sowb. (^=Pleurot. fHSColineata, C. B. Adams,= P. sealpta, Eeeve), P. pygmcea, C. B. Ad., P. maculata, C. B. Ad.,P. minor, C. B. Ad., P. piperata, Smith, and P. trifilosa, Smith, allbelong to this section.The present species is remarkable on account of the proportionallylarge size of the smooth nucleus, consisting of four and a halfvolutions.13. Terehra habylonica, Lamarck.Marie-Louise Island, Amirantes, 20 fms.14. Terelbra cerithina.{Lamarck) Kiener, Coq. Viv. pi. 11. fig. 25 ; So^oerhy, T/iesatirns, vol. i.pi. 43. fig. 68 ; Reeve, Conch. Icon. vol. xii. figs. 38 a, h.Var. ? = Terebra eburnea, Hinds, Thesaurus, vol. i. pi. 45. fig. 123.Juv. = Terebra pulcbra, Hinds, I. c. fig. 129 ; Reeve, I. c sp. 155.Providence Reef, Mascarenes, 24 fms.In the Museum there are specimens from the Seychelles andPhilippine Islands, N.E. Australia, Timor, Marquesas and SocietyIslands.15. Terebra dimidiata, juv.Cerf Island, Mascarenes, 10 fms.16. Terebra bruguieri.Deshayes, Proc. Zool. Soc. 1859, p. 297 ;Reeve, Conch, Icon. vol. xii.Terebra hindsii, Deshayes, Journ. de Conch, vol. vi. pi. 5. fig. 5.He des Roches, Amirantes, 13 fms.Other localities for this species are China (Deshayes) and SeychelleIslands {E. P. Wright, in Brit. Mus.).