Dimensions.—Shell 0.036 diameter; horn 1 to 1.5 mm. long, feet 0.3 to 0.4 long.
Habitat.—Central Pacific, Station 270, surface.
4. Tetraspyris calcarata, n. sp.
Shell campanulate, smooth, very similar to that of the preceding species, but differing in the following characters:—the two inferior occipital pores are four times (in the preceding twice) as large as the two superior; the apical horn bears at its distal end only three simple branches; the sternal foot is smaller than the three others, arises higher, is more divergent and curved, and bears at its base a large horizontal conical spur.
Dimensions.—Shell 0.035 diameter; horn 1 to 1.2 long, feet 0.2 to 0.3 long.
Habitat.—Central Pacific, Station 266, surface.
5. Tetraspyris scoparia, n. sp.
Shell campanulate, rough, very similar to the two preceding species, but differing in the following characters:—the four occipital pores are of nearly equal size; the apical horn is simple, not branched; the four feet are forked near the base, so that apparently eight feet diverge, each in the distal half richly branched, besom-shaped.
Dimensions.—Shell 0.038 diameter; horn 1 to 1.1 long, feet 0.4 to 0.5 long.
Habitat.—Central Pacific, Station 268, surface.