Habitat.—Pacific, central area, Station 263, depth 2650 fathoms.
Subgenus 2. Pentalastromma, Haeckel.
Definition.—Arms of different sizes, one odd arm larger than the two others; the opposite odd angle generally different from the four other angles.
3. Pentalastrum ophidiaster, n. sp. (Pl. [44], fig. 3).
Arms nearly triangular, at their obtuse truncated distal end twice as broad as at their base. Four arms equal, with five joints each; the fifth arm twice as long, with seven joints. Angles between the arms nearly equal; the odd angle a little larger.
Dimensions.—Radius of the larger odd arm 0.25, of the four smaller arms 0.15; basal breadth 0.035, distal breadth 0.07.
Habitat.—Pacific, central area, Station 274, surface.
4. Pentalastrum cometa, n. sp.
Arms nearly cylindrical, at their obtuse truncated distal end one and a half times as broad as at their base. Posterior odd arm very large, with eleven joints, about three times as long as the two lateral arms (with five joints each) and four times as long as the two anterior arms (with three joints each). Angles between the paired arms different; the two lateral angles smaller than the two posterior, and these smaller than the odd anterior angle.
Dimensions.—Radius of the odd posterior arm 0.5, of the lateral arms 0.25, of the anterior arms 0.18; basal breadth 0.05, distal breadth 0.08.