Habitat.—Cosmopolitan; Mediterranean, Atlantic, Indian, Pacific, surface.
2. Lithocircus quadricornis, n. sp. (Pl. [81], fig. 9).
Gate square. Ring square, with three sharp denticulate edges, and four large bunches of richly branched spines on the four corners. In each corner arise three curved spines, about as long as the diameter of the ring; their numerous irregular branches are forked and curved like the antlers of deer.
Dimensions.—Diameter of the gate 0.07; length of the horns 0.06 to 0.09.
Habitat.—South Pacific, Station 300, depth 1375 fathoms.
3. Lithocircus decimalis, n. sp. (Pl. [81], fig. 15).
Gate elliptical. Ring pentagonal, with three prominent edges and five pairs of branched spines on the five corners. In each corner arise two or three curved spines, about as long as the radius of the gate, each with two to four forked branches.
Dimensions.—Diameter of the gate 0.08; length of the spines 0.03 to 0.05.
Habitat.—North Atlantic, Station 354, surface.
4. Lithocircus hexablastus, n. sp. (Pl. [81], fig. 17).