OCR Text |
Show 72 MR. G. F. ANGAS ON [Jan. 15, 3. Descriptions of seven n e w Species of Land-Shells recently collected in Costa Rica by M r . Adolphe Boucard. By GEORGE FRENCH ANGAS, C.M.Z.S., F.L.S., &c. [Eeceived November 17, 1877.] (Plate V.) HELIX BOUCARDI, n. s. (Plate V. figs. 5, 6, 7.) Shell narrowly and profoundly umbilicated, depressedly conical, moderately thin, very finely radiately striated, white, the upper surface ornamented with two fawn-coloured bands passing into chocolate towards the apical whorls, or entirely fawn-colour, with a narrow effuse chocolate band next to the periphery ; whorls 4\, somewhat convex, strongly bluntly keeled at the periphery, with an impressed groove below the keel; apex obtuse, tinged with violet; sutures impressed, bordered with a narrow chesnut line ; base convex, white ; umbilicus dark brown ; umbilical region tinged with lemon-yellow; aperture very oblique, narrowly quadrately ovate, pale violet within; outer lip a little expanded and reflexed, slightly sinuate and projected above, arcuate below. Diam. maj. 13 lines, min. 10, alt. 7. Hab. Navarro, Costa Rica ; on leaves of trees. (Mus. Boucard.) HELIX ADELA, n. s. (Plate V. figs. 8, 9, 10.) Shell umbilicated, discoidal, flattened, very finely radiately striated, pale straw-colour, ornamented with a single narrow black band just above the periphery of the last whorl; whorls 3^, somewhat convex ; spire very much depressed; base flatly convex, with an excavated area around the umbilicus which is shallow and non-perspective; aperture horizontal, narrowly oblongly ovate; outer lip slightly expanded and reflexed. Diam. maj. 12 lines, min. 9, alt. 4. Hab. Novarro, Costa Rica, on trees. (Mus. Boucard.) HELIX ^ESOPUS, n. s. (Plate V. figs. 11, 12.) Shell umbilicated, depressedly conoidal, moderately solid, very finely obliquely striated and finely granulated, the granules being denser on the last whorl and obsolete towards the apex, brown, with a pale suffused band at the periphery of the last whorl; whorls 5, somewhat convex, the last bluntly keeled, contracted and deflected behind the outer lip; apex obtuse; base rather flattened; aperture horizontal, ear-shaped, brown, with a prominent, erect, slightly undulating, lamelliform, transverse ridge within upon the wall of the body-whorl; peristome white, somewhat thickened and reflexed, with a short blunt tooth at the base of the columella and a longer compressed triangular one incurved within the aperture opposite the ridge on the body-whorl ; margins united by an erect lamella. Diam. maj. 12 lines, min. 10, alt. 6. |