Abstract.  Middle Permian ammonoid faunas are recognized from the Hosoo and Kamiyasse
Formations in the Kaniiyasse-Imo district, north of Kesennuma, Southern Kitakami Massif,
Northeast Japan.  The faunas comprise the following genera: Parastacheoceras, Demarezites,
Demarezites?, Waagenoceras, Timorites, Tauroceras?, Cardiella, Adrianites, Agathiceras,
Agathiceras?, Paraceltites and Cibolites. Parastacheoceras bidentatus gen. and sp. nov.
is newly proposed. The genera Demarezites, Tauroceras, Cardiella and Adrianites are
described for first time from Japan.  Based on these ammonoids, the middle part of the
Hosoo Formation, upper part of the Hosoo Formation to the lower middle part of the
Kamiyasse Formation, and upper middle part of the Kamiyasse Formation are correlatable
with the Middle Permian Roadian, Wordian and Capitanian, respectively.  The discovery
of genera Demarezites and Cardiella strongly supports the previous hypothesis that
the South Kitakami Paleoland was located in the equatorial province during the Middle Permian.