First record of Cercyon (s. str.) inquinatus Wollaston, 1854 from Turkey with notes about this problematic species (Coleoptera: Hydrophilidae: Sphaeridiinae: Megasternini).

Cercyon (s. str.) inquinatus Wollaston, 1854 is recorded for the first time from Turkey. It was found in the darkest part of a vast cave occupied by an underground river and pools. The specimens were collected, in or near water, without being sure that they are aquatic and subterranean. Bright and black or blackish body, pronotum with a slight partial and median groove, rather convex interstries, male genitalia are quite characteristic. The habitat and sampling methods are described. The difficulty of identifying the insect with existing keys is exposed and analyzed. Photos of Turkish specimen and a list of the associated fauna are provided.