Marine cephalopod mollusc with mantle extremely long and narrow. Tail (fins and posterior mantle projection) extremely long and spike-like. Fins oval in outline; posterior border of fins concave;arms very short. Diameters of club suckers of median 2 rows 3 times greater than lateral ones. Left ventral arm (IV) hectocotylized by modification of distal 2/5 of length; 8 to 11 pairs of normal suckers proximally followed by longitudinal rows of more or less elongate papilla that gradually decrease in size distally. Maximum mantle length 19 cm.