1. Coronidium dyostephanus, n. sp. (Pl. [82], fig. 7).
Frontal ring elliptical, with few scattered thorns, twice as broad as high, and three times as broad as the smooth rhombic basal ring. Sagittal ring semicircular, very stout, twice as thick as the two other rings, with short lateral thorns (in the figure seen from the apical pole, which exhibits a four-lobed dimple). Basal gate rhombic.
Dimensions.—Height of the frontal ring 0.08, breadth 0.16.
Habitat.—Central Pacific, Station 263, depth 2650 fathoms.
2. Coronidium diadema, n. sp. (Pl. [82], fig. 8).
Frontal ring kidney-shaped, one and a half times as broad as high, with a slight sagittal constriction. Sagittal ring ovate, smaller, about of the same size as the elliptical basal ring. Rods of all three rings cylindrical, bearing numerous short and stout curved spines, partly simple, partly branched. Four bunches of larger spines on the four corners of the basal ring, and one very large bunch on the apical pole. Basal gate elliptical, one and a half times as broad as long.
Dimensions.—Height of the frontal ring 0.13, breadth 0.18.
Habitat.—Indian Ocean (Madagascar), Rabbe, surface.
3. Coronidium cervicorne, n. sp. (Pl. [82], fig. 1).
Frontal ring kidney-shaped, twice as broad as high, one and a half times as broad as the elliptical basal ring, both with a slight sagittal constriction. Sagittal ring ovate. All three rings (in the figure seen from the apical pole) with cylindrical rods, armed with numerous stout spines, branched like a deer's antler. Basal gate rather oblong, twice as broad as long.