prismatic, about as long as the shell diameter, somewhat curved. The apical horn stands on the apex, the frontal horn half-way up the shell.
Dimensions.—Shell 0.08 long, 0.06 broad; horns and feet 0.05 to 0.07 long.
Habitat.—Central Pacific, Station 272, depth 2600 fathoms.
3. Archipera bicornis, n. sp.
Shell ovate, rough, with small regular circular, sparsely scattered pores. Basal plate with four larger central and a peripheral coronal of twelve smaller pores. Two horns near the apex widely divergent, somewhat shorter than the shell, of equal size and similar form. Three feet twice as long, horizontally expanded. All five spines slender, three-sided pyramidal, straight.
Dimensions.—Shell 0.07 long, 0.06 broad; horns 0.05 long, feet 0.1 long.
Habitat.—Central Pacific, Station 271, depth 2425 fathoms.
4. Archipera tricornis, n. sp.
Shell subspherical, smooth, with subregular circular pores. Basal plate with four large meshes (two major cardinal and two minor jugular pores). On the apex three divergent pyramidal horns of different size, one larger occipital and two smaller frontal horns. Three feet prismatic, about twice as long as the shell.
Dimensions.—Shell diameter 0.05, length of the feet 0.1.
Habitat.—North Pacific, Station 253, depth 3125 fathoms.
5. Archipera quadricornis, n. sp.
Shell ovate, smooth, with a small number of irregular roundish, widely scattered pores. Basal plate with four crossed meshes of nearly equal size. On the equator there arise four divergent prismatic horns of nearly equal size, three of which correspond to the three feet, whilst the fourth is opposite to the caudal foot. The three feet are also prismatic, as long as the shell, horizontally expanded. (Similar to the upper half of Lithomelissa decacantha, Pl. 56, fig. 2, but without thorax.)
Dimensions.—Shell 0.05 long, 0.04 broad; horns and feet 0.06 long.
Habitat.—South Pacific, Station 300, depth 1375 fathoms.
6. Archipera multicornis, n. sp.
Shell hemispherical, spiny, with irregular polygonal pores. Basal plate with six meshes (?). Between the smaller spines of the surface arise six larger conical divergent horns. Three feet also conical, divergent, about twice as long as the shell and the horns.
Dimensions.—Shell 0.05 long, 0.07 broad; horns 0.05 long, feet 0.1 long.
Habitat.—Central Pacific, Station 274, depth 2750 fathoms.
