Definition.—Four large equatorial spines provided with transverse apophyses; sixteen other smaller spines simple, without apophyses.
1. Quadrilonche tetrastaura, n. sp.
Four equatorial spines very large, compressed, two-edged, each crossed in the distal third by two opposite simple apophyses. Sixteen other spines also compressed, linear, somewhat shorter than the former and only half as broad, without apophyses.
Dimensions.—Length of the four major spines 0.12, breadth 0.02; length of the sixteen minor spines 0.08, breadth 0.01.
Habitat.—Central Pacific, Station 266, surface.
2. Quadrilonche platystaura, n. sp. (Pl. [131], fig. 2).
Four equatorial spines lanceolate, compressed, with two opposite triangular simple apophyses in the broadest middle part. Sixteen other spines also lanceolate, much smaller, of about half the length, but only of one-fourth the breadth, without apophyses.
Dimensions.—Length of the four major spines 0.2, breadth 0.018; length of the sixteen minor spines 0.1, breadth 0.004.
Habitat.—North Pacific, Station 235, surface.