Adelomelon brasiliana: Shell medium to large in size, subglobose, heavy, smooth or tuberculide and with a thick periostracum, reaching a length of 188 mm. (7,25 inches) solid, imperforate and nodulose. Color grayish white, overlaid with a thick, blackish brown periostracum. Aperture a light, brownish orange. Whorls 6, and moderately convex. Spire only slightly extended and produced at an angle of about 105°. Aperture semicircular. Siphonal canal broad and shallow, which has produced in its previous growth stages a well-marked fasciole. Outer lip simple. Parietal area with a heavy glaze which is sharply margined. There are two to four plicae, the lower one being the largest. Columella short and arched. Suture slightly indented. Sculpture consisting of numerous, line to coarse growth lines. On the whorl shoulder there is a single row of well-developed knobs. Protoconch with one and one-half whorls and rather small. Probably without an operculum. The foot, head and siphonal canal are colored a finely mottled purple, the foot about equal to the length of the shell. The young are subglobose and have a very short rounded calcarella. The young of A. ancilla Solander are attenuated and have an extended, pointed calcarella. The radula is typical of that for the genus, but the shell and protoconch differ from typical Adelomelon.

Adelomelon brasiliana: Range. From the southern coast of Brazil and south at least as far as Deseado, Pata¬gonia, Argentina. Carcelles reports it to be very abundant on the sandy beaches at Cabo San Antonio and at Mar del Plata. Argen¬tina. It occurs in the intertidal and littoral zones.