Torinoko block mountain mainly consists of sandstone, shale and rarely conglomerate ; but its geological age is unknown, for fossils are very rare in these formations., We discovered a few Palaeozoic fossils of Brachiopoda and Foraminifera in limestone pebbles in the conglomerate taken from the older rock formation at Sarukubo, Senda valley, Yasato village, Naka-gun, Ibaragi Prefecture in 1944., According to H., Fujimoto, the Brachiopoda are of Martinia sp., and some of the Foraminifera are of Pachyphloia sp., and the others are of Schwagerina sp., ; and these fossils indicate to belong to the Permian period., Therefore the geological age of the older rock formation is considered to be post Permian period.,