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Show 1890.] MARINE MOLLUSCA OF ST. HELENA. 295 lata; apertura rotundata; peristoma leviter incrassatum, marginibus continuis, clextro subpatulo. Longit. \ millim., diam. maj. Ii. The beauty of this species can only be seen under the microscope. The cancellation of the body-whorl is strongly developed, so that the pittings between the cross-ridges are deep and striking. The uppermost of the six revolving lirce borders the channelled suture, and the umbilicus is encompassed by a swollen ridge, which is in addition to the six lirae referred to. The microscopic strife are seen upon the lirae. LIOTIA ADMIRABILIS. (Plate XXIV. fig. 7.) Testa minuta, profunde umbilicata, depresse globosa, cdba ; anfractus '6\, superne declives, planulati, in medio angulati, infra angulum plani, cancellati, ultimus carinis transversis quinque, lamellis longitudinalibus paulo obliquis circiter 16 instructus ; apertura circulates; peristoma incrassatum, continuum, marginibus callo tenui junctis. Longit. 1 millim., diam. maj. lg. This very minute species is a strongly sculptured shell like L. asteriscus, Gould, and L. speciosa, Angas. It is, however, much smaller than either. Tbe uppermost of the keels on the body-whorl revolves up the spire and forms the angle on the upper volutions; the lowermost carina borders the umbilicus, and the next occupies the middle of the under surface. The longitudinal lamelhe are continuous on and between the keels. GENA ASPERULATA, A. Adams. Gena asperulata, A. Adams, Proc. Zool. Soc. 1850, p. 38; Thes. Conch, vol. ii. p. 831, pi. 173. figs. 28, 29; Sowerby, Conch. Icon. pi. ii. fig. 16. Hab.-1 (Adams); St. Thomas (Brit. Mus.). The colour of this species is very variable. Some specimens are pink, tessellated with white; others are olive-brown with white spots; some have few spots, others many. None of the St. Helena shells are marked like the type, but they agree with it in form and sculpture, which is peculiar, and in having the apex of the spire white. EMARGINULA ELONGATA, Costa. Hab. Mediterranean. A single small specimen, 5 millim. in length, apparently belongs to this species. The cancellation of its surface is, however, a little finer than usual. E. maculata, A. Adams, from Japan, also closely resembles this specimen in form and sculpture. FISSURELLA GIBBERULA, Lamarck ? Several specimens, the largest of which is hardly ten millim. long, appear to belong to this species. F. variegata, Sow., and |
