1. There are many large and small fusulinid-bearing limestone lenses in th-e Titibu System of this region. The fossil localities and important fossils are enumerated. 2. The geological ages of the limestone lenses are found to range f-rom the Moscovian to the Middle Permian, on the evidence of the Fusulinids cont-ained in them. 3. Four fossil zones are distinguished. (IV) Zone of Neoschuager-ina craticulifera (SCHWAGER) and Schuagerina japonica (GUMBEL) (III) Zone of Neoschuagerina nipponica (OZAWA) and Schuagerina knaffti (SCHELLWIEN) (II) Zone of Paraschuagerina oblonga (OZAWA) and Schuagerina vulgaris (SCHELLWIEN) (I) Zone of Fusulinella biconica (HAYASAKA) 4. These fossil zones are correlated with those of Nagato, Akasaka, the Kwanto and Suzuka Mountainlands.