Matsumoto, H. (1937)
A New Species of Orc from the Basal Calabrian at Naganuma, Minato Town, Province of Kazusa, Japan. (in Japanese)
Zoological Magazine, 49(8), 191–193
Matsumoto, H. (1936)
Upper Miocene vertebrates from Kumanodô, Natori district, province of Rikuzen.
Dobutsugaku Zasshi (= Zoological Magazine Tokyo), 48, 475–480