Ishiyama, R. (1952). Studies on the rays and skates belonging to the family Rajidae, found in Japan and adjacent regions. 4. A revision of three genera of Japanese rajids with descriptions of one new genus and four new species mostly occured in northern Japan.
Journal of the Shimonoseki College of Fisheries. v. 2 (no. 2): 1-34, Pls. 1-4.