Galeodea rugosa is a large, elongate species resembling G. alcocki in most characters, although most specimens have a shorter spire and more inflated spire whorls than G. alcocki, so that it is not so smoothly, narrowly and evenly fusiform as G. alcocki. Also, all specimens examined have a wide, prominent, rather thin, smooth inner lip collar raised above the previous whorl over the neck, extending to the left from the inner lip; a free collar is not present in the specimens of G. alcocki I have seen. The outer lip is much more strongly flared outwards and thickened and ridged on the interior than in G. alcocki, producing a much wider and more obvious terminal varix than in G. alcocki, and rendering the aperture unusually narrow. The smooth, even, round-topped, rather widely spaced spiral cords and the moderately long, weakly twisted siphonal canal are similar in the two species. Galeodea rugosa differs from the partly sympatric species G. echinophora in its much larger size, its more elongate shape, its more prominent spiral cords, and in most specimens lacking peripheral nodules, whereas several rows of peripheral nodules are present in most specimens of G. echinophora.
Although an unusually dark brown, the operculum of Galeodea rugosa is typical of Galeodea, with its nucleus near the right edge at a third to almost half of the opercular height from the anterior end of the operculum, and with a weak furrow near and parallel to the right margin, above and below the nucleus. I have not examined an animal, but the anatomy was described by Reynell (1905, 1906) and agrees with that of all the other species studied here; Reynell (1905) recorded and illustrated obvious, deeply pigmented eyes.

Diagnostic characters
Shell large, solid, glossy, with short, sharply pointed spire; last whorl large. Whorls bear many narrow spiral ridges but are without costae. Outer lip is often everted, bears an external varix and is marked internally by a ridged fold. Base of aperture forms a short siphonai canal. Columellar lip extended into thin flange overhanging umbilical groove.

Other characters
There are 7-8 slightly swollen whorls in this shell, with deep sutures. The spiral ridges are a little narrower than the grooves between, number about 35 on the last whorl (lying closer at its base), and 7-8 on each whorl in the spire. The aperture is surrounded by a peristome, more or less oval, and broader towards the adapical end; the throat narrows rapidly. The inner lip forms a smooth sheet over the last whorl. Cream, often browner at the base. Large specimens up to 120mm high, 70mm broad; last whorl occupies about three quarters of shell height, aperture about 60%.
The head ends in a transverse ridge and has no snout. Tentacles, each with a lateral, basal eye, arise from the ridge under which is the apparent mouth. The mantle edge forms a siphon on the left. Males have a penis behind the right tentacle. The foot is shield-shaped, broadly truncated anteriorly, bluntly rounded posteriorly.
G. rugosa is a southern species reaching its northern limits in the southernmost parts of the British Isles. Specimens have been found off south-west Ireland, Scilly, and in St George's Channel, less than twenty in all, and hardly any recently (Marshall, 1911; Massy, 1930; O'Riordan, 1984,1985). The animals live on soft bottoms, 70-700 m deep. They are carnivores, probably attacking echinoderms and other molluscs.

Galeodea rugosa occurs in the western Mediterranean, and in the eastern Atlantic from west of Ireland to southern Morocco (southernmost record 22°52,N). Bouchet & Waren (1993) considered that the few records from the western part of the eastern Mediterranean require confirmation. It is common in the Ibero-Moroccan Gulf, and fishermen net large numbers off southern Portugal (Beu, personal observation). Fossils occur not uncommonly in the Pliocene and Pleistocene of Italy and along the French Mediterranean coast.