Abstract
Three fossil species of Callianassa have been described from Japan, all from Hokkaidô; they are Callianassa ezoensis NAGAO, the Upper Cretaceous Hakobuti Sandstone.
C. muratai NAGAO, the Neogene Poronai series and the lower part of the overlying Kawabata series, and C. inornata NAGAO and HUZIOKA, the lower part of the Kawabata.
The species, to be described in the present short note, has been derived from the Palaeogene Isikari series. The Isikari series, underlaid by the Hakobuti and overlain by the Poronai, is subdivided into three parts, the terrestrial and coalbearing Lower Isikari, the marine Middle Isikari or the Wakkanabe bed, and the Upper Isikari which is composed of marine and brackish or fresh-water sediments and intercalated seams of coal. The new Callianassa has been collected from the Wakkanabe bed exposed along the Sorati-gawa in the Isikari coal-field.
