Habitat.—Antarctic Ocean, Station 157, depth 1950 fathoms.
3. Hexaplagia collaris, n. sp.
Spines in opposite pairs in three diameters, crossed in the common centre, straight, cylindrical, pinnate, with three to four pairs of opposite lateral branches or regular pinnulæ. All six spines are equidistant, of equal size and similar form, and lie with their branches nearly in one horizontal plane. Therefore they are similar to the six radial rods in the collar septum of many Spyroidea and Cyrtoidea (e.g., Calpophæna, Pl. [53], fig. 18).
Dimensions.—Length of all six spines 0.18, of their basal pinnulæ 0.04.
Habitat.—East of New Zealand, Station 169, surface.
4. Hexaplagia australis, n. sp.
Spines unequal, at unequal intervals, not opposite in pairs, cylindrical, irregularly branched and curved. In this species a definite arrangement of the six different spines could not be detected.
Dimensions.—Length of the spines 0.2 to 0.3, of their largest branches 0.1.
Habitat.—South of Australia, Station 160, surface.