Agauopsis (Acari, Halacaridae) of the Sevastopol area; supplementary notes on taxonomy and ecology. -Females, males and juveniles of Agauopsis inalinovi Petrova, and the two closely related species A. brevipalpus (Trouessart) and A. ibssi sp. n. are described. A. marinovi is found in large numbers in deep layers of beaches with very coarse, unsorted sediment. A. ibssi, which is also psammophilous, is the dominating halacarid species in coarse subtidal sand. A. brevipalpus is an inhabitant of bushy, green, brown and red algae.