Gonatopsis spp.

* Recently several Gonatopsis specimens which are thought to be undescribed species were obtaind form deep-sea （1500-2000m depth） off Sanriku. They resemble G. borealis but differ by having much selnder masuclar mantle. This Gonatopsis sp. matures at about 20 cm ML. Lower beaks of G. sp. can be distinguished from that of G. borealis of the same size by following points.

　　　Lateral wall angle narrow 32-35°; wing teeth trapezoidal projected at shoulder---
Gonatopsis borealis　
　　　

　Lateral wall angle wide about 50°; wing teeth low ---
Gonatopsis sp.
　　　　