Zeacumantus estuarina: Shell elongate, stoutish ; apex acute; whorls about twelve, convex, the uppermost whorls angulated medially, covered with a bluish-black to grey epidermis beneath which the colour is reddish; suture distinct. Base convex. Aperture circular, slightly angulated and effuse at the base of the columella j shining-black within; outer lip thin and arcuate; columella arched, obliquely excavated so as to form a slightly-raised border exteriorly. Operculum circular and multispiral. Ornament consisting of depressed spiral threads, five or six on the penultimate whorl, and of slightly-arched plica; (from eleven to fifteen on penultimate whorl) which terminate abruptly at the second lira from the anterior suture ; the lirae as they pass over the plicae produce nodular crenatures : the whole surface is sculptured with tine arcuate striae. The plicae vary much in strength, rarely obsolete ; in the latter case the shell approximates to B. lawleyanum, from which it is conspicuously distinguished by its elongate form, less dense, and more threadlike spiral ornament. The base is concentrically ridged and transversely striated. Dimensions of a large specimen: length 22 mm, major diameter of base, 5 mm ; of a medium-sized specimen, length 17 mm, major diameter of body-whorl, 4,5 mm. The proportion of length to the basal diameter varies from 100 to 22,5 to 100 to 33 ; but the extremely-broad forms are rare.

Shell small, subulate, spirally grooved, thin. Sculpture con¬sisting of subequidistant spiral grooves, about 8 on the penultimate whorl, sometimes with distant broad axial plications and numerous fine growth-lines ; base with 1 or 2 grooves near the periphery, centre smooth ; some specimens show low varices. Colour bluish, white-banded. Spire high, a little over three times the height of the aperture ; outlines straight. Protoconch minute, mostly eroded. Whorls about 11, flatly convex, slowly increasing; base flatly convex. Suture deep. Aperture oblique, ovate, slightly channelled above, slightly notched and effuse below, but no distinct canal. Outer lip sharp, but slightly convex. Basal lip extending a little below the columella truncation. Columella straight. Inner lip very narrow, spreading over the body to the outer lip. Operculum normal.
Height, 10 mm.
Type.—Collection of the " Journal de Conchyliologie," Paris. Hab.—New Zealand. Australia and Tasmania.

Zeacumantus estuarina: The plicate ornament without distinctive granulation reduces the comparison of this species to a very few congeners; but the non-plicate suprasutural area, the number of the spiral lirae and the elongate form separate it from all of them.

Zeacumantus estuarina: Australia. Living on the mud, between tide-marks, Port Adelaide Creek ; Franklin Barbour