5. Staurotholus decastylus, n. sp.
The two principal cupolas twice as broad and high as the two lateral cupolas. Pores subregular, circular, four times as broad as the bars; six to eight in the semicircle of one cupola. Ten long and thin radial spines with thickened conical bases, about as long as the major axis of the shell, by inner prolongations connected with the lentelliptical medullary shell; two polar spines in the principal axis, eight wing-spines in two crossed diagonal planes.
Dimensions.—Major axis 0.12, minor 0.1; pores 0.012, bars 0.003.
Habitat.—Western Tropical Pacific; Station 224, depth 1850 fathoms.
6. Staurotholus dodecastylus, n. sp. (Pl. [10], fig. 9).
The two lateral cupolas larger than the two principal cupolas. Pores subregular, circular, three times as broad as the bars; five to seven in the semicircle of one cupola. Twelve strong cylindrical radial spines, four on the poles of the two larger axes (two principal and two lateral), eight wing-spines in two crossed diagonal planes. Medullary shell hexagonal.
Dimensions.—Major (lateral) axis 0.11, minor (principal) 0.09; pores 0.009, bars 0.003.
Habitat.—Tropical Atlantic, Station 348, surface.
7. Staurotholus polystylus, n. sp.
The two principal cupolas larger than the two lateral cupolas. Pores irregular, roundish, twice to three times as broad as the bars; ten to twelve in the semicircle of one cupola. On the surface numerous thin bristle-shaped spines (twenty to thirty or more).