THE SHELL ZONE OF LAKE KITAURA

Abstract

The benthos of Lake Kitaura, Ibaragi Prefecture was surveyed in August and November of 1964. 1. A shell zone was found in this lake. 2. The shell zone is situated at the depth, not influenced by wave action. 3. At the stations Futaesaku, Kajiyama, the shell zone is composed largely of the shells of Sinotaia histrica. At Uzaki and Tsumaki, where the sea water invades more than the aforesaid stations, the shell zone is composed mainly of the shells of Corbicula japonica.