Habitat.—Indian Ocean, Madagascar, Rabbe.
Subgenus 2. Xiphacanthidium, Haeckel.
Definition.—Apophyses of the radial spines broad, compressed, wing-shaped, formed like a large thin plate. Edges of the spines commonly broad, strongly prominent.
7. Xiphacantha stauroptera, n. sp.
Spines four-winged, from the middle part little thinner towards both ends. Apex simple pyramidal. Base with small wing-cross. Four apophyses wing-shaped, isosceles triangular or truncated quadrangular; their base is about half as broad as their length, and occupies in the basal half of each spine about one-sixth to one-eighth of its length.
Dimensions.—Length of the spines 0.1 to 0.15; greatest breadth (diagonal of the cross of the apophyses) 0.006 to 0.009.
Habitat.—South Atlantic, Station 332, surface.
8. Xiphacantha trigonoptera, n. sp.
Spines four-winged, tapering rapidly from the broad middle part towards both ends. Apex simple pyramidal. Base with a small wing-cross. Four apophyses equilateral triangular; their base occupies the middle of each spine, extending to about one-fifth of its length.
Dimensions.—Length of the spines 0.15 to 0.2, greatest breadth (diagonal of the cross of the apophyses) 0.06 to 0.08.