Echinophoria bituberculosa is very distinctive in being taller and narrower than the other Recent species of Echinophoria, and is intermediate in size between the larger species, E. coronadoi and E. wyvillei, and the smaller species E. carnosa. All specimens have a narrow but thick, clearly raised callus collar extending from the inner lip over the most constricted part of the neck, hiding the narrow false umbilicus. The degree of development of the collar and of its transverse ridges varies greatly, and some specimens with only weakly sculptured exteriors have coarse, prominent transverse ridges on the inner lip, extending across the collar (e.g., one of the 2 specimens in PI, chalutage 5, off Madagascar, 570-563 m), whereas others with or without obvious spiral sculpture have an almost completely smooth collar. The width of the shell and the strength of the spiral sculpture vary greatly in the available material, so although all specimens have many low, obvious, closely spaced spiral cords on the first one or two teleoconch whorls, the cords may remain unchanged throughout growth, may strengthen down the shell to produce the prominent cords of the typical E. bituberculosa form, or may fade out altogether by the end of the last whorl. Animals were not available for examination. DIMENSIONS. - Holotype of Echinophoria bituberculosa: H 45, D 30.1 mm; MNHN, off Somalia: H 85.5, D 51.2 mm; H 52.0, D 33.6 mm; MNHN, Reunion, coll. Gueze: H 70.8, D 47.8 mm; MNHN, PI chalutage 5, Madagascar: H 74.0, D 47.2 mm; H 70.7, D 46.7 mm.

TYPE MATERIAL. - Cassis bituberculosa: holotype in Humboldt Museum, University of Berlin, ZMB 60052 (Abbott 1968: 103), from Valdivia stn 264, 1079 m, c. 160 km NNE of Obbia, Somalia, East Africa, 6°18'N, 49°32*E (not seen).
DISTRIBUTION. — Echinophoria bituberculosa occurs throughout the western Indian Ocean, possibly as far north as the Gulf of Aden, south to southern Mozambique, and at Madagascar and Reunion, in c. 200-600 m (the depth of the holotype of E. bituberculosa probably refers to an empty shell carried down slope). It is much less common than Galeodea keyteri in MNHN material from off Madagascar.