2. Unio Burtoni, n. sp. (Pl. XLVII. fig. 1.)
Shell small, oval, rather thin, somewhat pointed behind; umbones small, not eroded; pale olive, concentrically furrowed, and sculptured more or less with fine divaricating lines; anterior teeth narrow, not prominent; posterior teeth laminar; pedal scar confluent with anterior adductor.
Length 12, breadth 81⁄2, thickness 51⁄2 lines.
Testa parva, ovalis, tenuiuscula, postice subattenuata; umbonibus parvis, acuminatis; epidermide pallide olivacea; valvis lineolis divaricatis, decussatum exaratis; dentibus cardinalibus angustis, haud prominentibus.
3. Lithoglyphus zonatus, n. sp. (Pl. XLVII. fig. 3.)
Shell orbicular, hemispherical; spire very small; aperture large, very oblique; umbilicus wide and shallow, with an open fissure in the young shell; lip continuous in front with the umbilical ridge; columella callous, ultimately covering the fissure; body-whirl flattened, pale olivaceous, with two brown bands, darker at the apex; lines of growth crossed by numerous oblique, interrupted striæ.
Diameter 5-6, height 3 lines.
Testa orbicularis, hemisphærica, late umbilicata (apud juniores rimata), spira minuta; apertura magna, valde obliqua; labio calloso (in testa adulta rimam tegente); pallide olivacea, fasciis duabus fuscis zonata; lineis incrementi striolis interruptis oblique decussatis.
4. Melania (Melanella) nassa, n. sp. (Pl. XLVII. fig. 4.)
Shell ovate, strong, pale brown, with (sometimes) two dark bands; spire shorter than the aperture; whirls flattened, ornamented with six brown spiral ridges crossed with a variable number of white, tuberculated, transverse ribs; base of body-whirl eight with tuberculated spiral ridges variegated with white and brown; aperture sinuated in front; outer lip simple; inner lip callous.