MELAMPUS. Montf. CONOVULUM, Lam. A genus composed of species of AURICULA, Auct. of a conical form. A. conoidalis, fig. 298. MELANIA. Auct. ([Greek: Melas], _melas_, black.) _Fam._ Melaniens, Lam. Ellipsostomata, Bl.--_Descr._ Turrited; spire generally elongated, acute; aperture entire, oval or oblong, pointed at the posterior extremity, rounded anteriorly, with a kind of indistinct canal or sinuosity: epidermis thick, generally black.--_Obs._ In common with other fresh-water shells, the Melaniæ are frequently found with corroded apices. This genus is known from Melanopsis by the absence of the notch at the anterior part of the aperture. The Melaniæ occur in rivers of warm climates. The fossil species are frequent in upper marine formations. Fig. 313, M. subulata. MELANIANA. Lam. (Melaniens.) A family belonging to the first section of the order Trachelipoda. The genera contained in it maybe distinguished as follows. 1. MELANOPSIS. Aperture notched; columellar lip thickened above; including _Pirena_. Fig. 315, 316. 2. MELANIA. Aperture not notched; columellar lip not thickened; including _Auculosa_, _Pasithæa_, _Io_. Fig. 313, 314, 317. MELANITHES. Sw. A sub-genus of Melanopsis. Sw. p. 341. MELANOIDES. Olivier. MELANOPSIS. Fer. MELANOPSIS. Fer. _Fam._ Melaniana, Lam. Entomostomata, Bl.--_Descr._ Oval or oblong, fusiform; spire acute, sometimes elongated; aperture oblong or oval, pyriform, with a distinct notch at the anterior extremity; columella tortuous, callous, thickened at the extremity near the spire; epidermis thick, horny, generally black. Subtropical.--_Obs._ This description includes the two first species of the genus Pirena, Lam. The Melanopsides are known from the Melaniæ by the notch in the aperture. Fig. 315. M. costata. MELAS. Montf. MELANIA, Auct. MELATOMA. Sw. A sub-genus of Melanopsis. Sw. p. 341. MELEAGRINA. Lam. MARGARITA. A genus composed of the Pearl Oyster and similar species, separated from Avicula on account of the roundness of their general form, but re-united by Sowerby. For generic characters, see Avicula. Fig. 164. M. margaritifera. MELEAGRIS. Montf. TURBO Pica, Auct. and similar species, having the aperture oblique, the columella gliding imperceptibly into the outer lip, and having an umbilicus. MELINA. Schum. PERNA, Auct.