Hysteroconcha dione

Hysteroconcha dione, also known as the elegant Venus clam, is a species of bivalve mollusc in the family Veneridae. The shell is whitish-pink with long, curved spines on each valve. It was first described by Carl Linnaeus in 1758 under the name *Venus dione* and later reclassified as *Hysteroconcha dione*. The generic name *Hysteroconcha* combines Greek and Latin roots, meaning "womb shell," while the specific epithet *dione* refers to Dione, the mother of Venus in Roman mythology.

The shells can reach up to 72 millimeters in length and are pale or whitish-pink with a whitish interior. Each valve features prominent, sharpened concentric ribs and a double series of long, curved spines on the posterior slope. This rare species is similar to *Pitar lupanaria*, which is found in the Eastern Pacific.

Hysteroconcha dione is distributed in the Gulf of Mexico, from eastern Mexico to the West Indies, and inhabits intertidal zones and moderately shallow waters. Linnaeus described the shell using sexually explicit terms like "vulva," "anus," and "nates" in his works *Systema Naturae* (1758) and *Fundamenta Testaceologiae* (1771). These descriptions were later criticized for being inappropriate, with some naturalists finding them uncomfortable despite their anatomical relevance.