Definition.—Both arms equal, of the same size and form, with terminal spines.
4. Amphibrachium amphilonche, n. sp.
Both arms equal, lanceolate, in the middle part four times as broad as at the two ends, twice as long as broad; on the distal end of each arm is a long conical spine.
Dimensions.—Radius of each arm (without terminal spine) 0.2, breadth 0.08.
Habitat.—Pacific, central area, Station 271, depth 2425 fathoms.
5. Amphibrachium capitatum, n. sp.
Both arms equal, club-shaped, three times as long as broad, in the outer distal half thickened, three times as broad as at the narrow base; on the distal end of each arm a strong, angular, terminal spine. (The form of the arms like that of Stephanastrum capitatum, Pl. [44], fig. 1.)
Dimensions.—Radius of each arm 0.22, basal breadth 0.02, terminal breadth 0.06.
Habitat.—Equatorial Atlantic, Station 347, surface.
6. Amphibrachium armatum, n. sp.