Saxicava Borings and Valves in a Boulder Clay Erratic

Abstract

WHEN examining a few weeks ago the boulders in the workings of the New Ferry Brick and Tile Company, Cheshire, with Mr. Harnett Harrisson, we discovered a boulder having superficially a scoriaceous appearance, which on examination proved to be of limestone, and perforated with Saxicava and other borings. After careful washing several of the burrows were found to be occupied by the shells of the animal that had made them, both valves complete. The washings that came out of the burrows after careful reduction by pouring off the clay water I found to consist of well-rounded grains of quartz intermixed with a few microscopic drift pebbles and small shell fragments. Some of them were very much rounded and waterworn. Several broken spines of Echinus also occurred.