Asymmetron inferum from off Cape Nomamisaki, southwestern end of Kagoshima Prefecture, at a depth of 229 m

A, the whole body, showing peculiar urostyloid process (arrow);

B, anterior part, showing a black pigment spot in neural tube (white arrowhead), low (thin arrow) and high (thick arrow) intertentacular membrane, and short mid-ventral tentacle (black arrowhead);

C, posterior part, showing atriopore (large asterisk), anus (small asterisk), abrupt ending of left metapleuron (thick arrow), and a vacuole between atriopore and anus (thin arrow).

Scale bars indicate 1 mm