Revision of the genus Benthobia (Caenogastropoda, Pseudolividae)

Abstract

A revision of the genus Benthobia Dall, 1889, which inhabits deep waters worldwide, is provided. In addition to B. tryonii, which inhabits the North Atlantic, four new species are described: B. atafona, from southeast Brazil; B. complexirhina from the Tasman Basin, Australia; B. tornatilis, from the Coral Sea, Australia and B. sima, from Madagascar. Species separations are based on conchological and anatomical features. An anatomical diagnosis for the genus is provided, leading to a discussion of the systematics of the family. Distinguishing anatomical characters for the genus include: eyes lacking; posterior furrow in foot sole; horseshoe-shaped attachment to operculum; single, massive, muscular and hollow accessory salivary gland with narrow duct; salivary gland separated into two parts; closed pallial sperm duct; penis with closed penial duct and broad, sub-terminal, dome-shaped papilla; pallial oviduct generally with a posterior seminal receptacle, and terminal, muscular bursa copulatrix positioned between vestibule and pore, partly attached to pallial floor. Most of the remaining features are typical of muricoideans. A discussion on the possible validity of Nux alabaster, from the Atlantic coast of South Africa, is provided; based on conchological, opercular and radular characters, it is concluded that it is closely related to Benthobia.