| OCR Text |
Show 1867-] DR. J. E. GRAY ON CATILLUS. 997 Fig. 2b. Li-..^ Fig. 2 a. Outer surface. Fig. 2 b. Inner surface. 15. CATILLUS CUMINGIANUS. (Operculum, Fig. 2.) Navicella cumingiana, Recluz; Reeve, f. 7. N. luzonica, Schlegel; Reeve, f. 11. Hab. Philippines. The opercula of this species are very variable in shape : some are much longer than broad, and have very acute lobes; this is especially the case in the smaller specimens. There are several other species figured by Mr. Reeve that probably belong to this species; but as they are destitute of opercula it is not possible to determine their true place in the system, or their affinity to the other species. Like other fluviatile shells, they are liable to great variations in size, form, and colour. 2. PARIA, n. g. Shell elliptical, mouth wide ; inner lip flat, shelving upwards, produced and truncated in the middle, with a roundish notch on each side near the margin of the cavity; operculum-shelly plate subquadrangular, lower edge straight, transverse, with a flexible flap, the upper edge with two lobes, the marginal lobe elongate, linear. * Shelly plate of operculum broad, flat, thin. 1. PARIA FREYCENETI. N.freyceneti, Recluz; Reeve, Icon. t. 1. f. 4. Hab. New Hebrides. ** Shelly plate of operculum narrow, high, solid, thick. 2. P A R I A PSITTACEA. N. psittacea, Re'cluz ; Reeve, Icon. f. 23. Hab. Australian Islands. Tribe II. STENOPOMINA. The operculum oblong elongate, narrow ; the horny (true) operculum triangular, very oblique as regards the axis of the shelly plate (occupying the triangular right half of the hinder half of the entire operculum), acute near the nucleus, and rounded at the end; shelly plate of the operculum elongate, thin, with two elongated ridges on the upper end, the marginal one produced into a sqiine, with a |
