Sasaki, 1929
Description:
Body is dorso-ventrally flattened. Mantle elongated oval and much larger than head; mantle length up to 20 cm; mantle width is about 30 % of its length. Anterior dorsal edge of mantle with a tongue-like projection. A large gland whose duct opens between the fins in form of a red spot lies under skin in postero-dorsal part of mantle. A row of several large brightly coloured spots extends along the fin base. Fins are narrow, extending from anterior to posterior edge of mantle. Arms with 2-4 rows of suckers. The 4th arm is considerably broader than the others, with a muscular swimming membrane. Tentacles are retractile. Club suckers in 16-32 rows (usually more than 20 rows). Sepion (shell) is narrow and tongue-like, without spine. Undersurface of sepion is concave in posterior half and, together with lateral edges of shell, forming a "fork" (inner cone). The internal shell is bordered by a lateral ridge that is wide in posterior half and narrow in anterior half of sepion. Ink sac is well developed.
Habitat:
Benthic, inhabiting continental shelf, sometimes reaching upper bathyal zone.
Distribution:
Exotic species (China, Philippine Islands); found occasionally in the North Sea (Distr. S. japonica).