“Euzonus (Thoracophelia) profundus, new species
Record: 5:7 sta. 112 (1, TYPE).
Description: A complete specimen measures 10 mm long, 2 mm wide in the anterior, or widest segment, and consists of 30 setigerous segments. The prostomium is acutely pointed and directed forward; it is slightly longer than wide. The first setigerous segment is the smallest one; it is slightly in front of the transverse oral aperture. Thereafter the body is inflated and abruptly constricted behind the second setigerous segment. The first 10 segments lack branchiae. They are followed by 15 segments, each with a pair of bifid branchiae in which the two branches are subequal and lack lateral processes. The short postbranchial region consists of five telescoped segments which taper posteriorly.
Only two species are known in the subgenus; they are Euzonus (Thoracophelia) furcif era Ehlers, 1897, from the Strait of Magellan, intertidal, and E. (T.) mucronata (Treadwell, 1914) from California, intertidal, The first has 20 pairs of branchiae and the pygidium has 5 pairs of dorsal papillae; the second has 18 pairs of branchiae and the pygidium has 7 pairs of dorsal papillae. E. (T.) profundus differs from both of these in having 15 pairs of branchiae and the pygidium has 3 pairs of papillae. It occurs in abyssal depths.
Distribution: Southeast off Cape Horn, in 4008 m.”