OCR Text |
Show 1880.] FROM CENTRAL AFRICA. 347 angulation at the middle, beneath which the costulate sculpture becomes almost obsolete and the surface comparatively smooth and shining. In the mature shell this angulation disappears, and the strength of the sculpture decreases insensibly. 5. ENNEA LATA, sp. nov. (Plate XXXI. figs. 4, 4 a.) Shell ovately pupiform, rimate, transparent white, thinnish, obliquely striated and finely serrated beneath the suture. Whorls 7, rather convex, penultimate nearly as broad as the last; this is attenuated somewhat at the base, ascends anteriorly, is faintly flattened in front above the aperture, where it is rather smoother than elsewhere. Spire obtuse, scarcely at all conoid at the apex. Aperture nearly vertical, occupying about three sevenths of the entire length, without teeth. Peristome a little thickened and everywhere narrowly reflexed. Columella dilated, united to the outer lip by a thin glossy callosity. Length 20 millims., diam. 11; aperture 9 long, 71 broad. E. anodon of Pfeiffer somewhat resembles this species. It is, however, smaller, more conical at the summit, and has a simple un-serrated suture. From the serrations or denticles flow downwards fine oblique but little raised costula?, which are scarcely observable to the unassisted eye. The labrum, viewed laterally, is seen to be obliquely but slightly curved ; the columella too is also sloped or receding. 6. ENNEA UJIJIENSIS, sp. nov. (Plate XXXI. fig. 5.) Shell elongate, cylindrical, thin, obliquely rimate, pale horny colour, obliquely costulate, the costulae being not much elevated, and prettily dentiform above at the suture. Whorls 10? Apex? The six remaining volutions are slightly convex, slowly increasing, the penultimate as broad or even a trifle broader than the last, which is deeply transversely grooved behind by two parallel furrows which do not extend quite to the lip. Aperture subvertical and subauriform, furnished with folds : one upon the paries is elevated, thin, lamellar, extending right within the mouth ; two others, equally large and reflexed at their top, are situated upon the outer lip, stretching far inwards, but not attaining to the margin; beneath these two and beneath the lower one there are one or two minor ridges. The columella has a subbasal oblique fold, and a smaller dentiform plait at the upper part. The peristome is prominent and a little expanded, the dextral margin being situated near the upper extremity and prominent in the middle, the columellar edge rather reflexed. Probable length 19 millims., actual length of six whorls 17 millims., diam. 54;; aperture 5 long, 4 wide. This species must be very closely related to E. papillifera, Jickeli, from Abyssinia, which is only known to me by description. The latter, however, is not half the length of E. ujijiensis, appears to be very finely striated and with five plicee within the aperture, whilst the present species is distinctly costulated and has two or three additional internal ridges. |