Thompson's false tun

The maximum recorded shell length is 81 mm, its diameter 56 mm. (Original description in French) The shell is imperforate and oval-ventricose It is characterized by its thin structure and reddish-tawny coloration, marked with irregularly distributed, large whitish spots. Its surface is transversely ribbed, with the interstices between ribs exhibiting one to three small spiral striae, crossed at right angles by very fine, nearly obsolete longitudinal striae. The spire is conical and slightly elevated, featuring a deeply marked and narrowly subcanaliculate suture. The shell comprises six convex whorls, with the body whorl being exceptionally large and swollen, constituting more than 6/8 of the total length. It is adorned with 56 ribs (excluding spiral striae) and terminates in a straight siphonal canal. The aperture is nearly oval, slightly acuminate near the insertion point, and whitish-tawny in its interior. The peristome is simple, with its edges connected by a thin, barely discernible callus, which thickens behind the columella and forms a tooth-like projection near the insertion point. The columellar edge is nearly vertical, folded, and white. The basal edge is slightly notched and purplish-pink. …

Offshore Barbados, Lesser Antilles, as crabbed shells in deepwater traps. This species has a cosmopolitan distribution, being also found in waters off Australia.