Subgenus Pentophiastromma, Haeckel.
Definition.—Arms of different size, one odd arm opposite to the angle between both arm-pairs.
2. Pentophiastrum caudatum, n. sp. (Pl. [47], fig. 5).
Arms in pairs different; four arms in the basal half simple, in the distal half forked; the fifth (posterior) odd arm simple, undivided, cylindrical; the anterior pair a little smaller than the posterior; the neighboring branches of the two pairs on each side larger than the two others. Axes of the arms and their branches straight.
Dimensions.—Radius of the arms about 0.5, breadth 0.12.
Habitat.—North Atlantic, Station 353, depth 2965 fathoms.
3. Pentophiastrum forcipatum, n. sp. (Pl. [47], fig. 4).
Arms in pairs different, all in the basal two thirds simple, in the distal third forked. Only in the posterior (odd) arm both branches are equal, in the four others unequal. The common axis of the posterior lateral pair is horizontal, perpendicular to the median line; the axes of the anterior pair are pincer-like, concavely curved towards the median line or principal axis.
Dimensions.—Radius of the arms about 0.5, breadth 0.14.
Habitat.—South Atlantic, Station 332, depth 2200 fathoms.