Dimensions.—Length of the central chamber 0.04, breadth 0.025; length of the lateral girdle 0.11, breadth 0.08; height of the gates 0.03, breadth 0.04.
Habitat.—Mediterranean (Genoa), Haeckel, (Messina), R. Hertwig, surface; Tropical Atlantic, Station 348, surface.
7. Trizonium staurobelonium, n. sp.
Central chamber spherical, with two opposite polar beams. Lateral girdle elliptical, one and a half times as long as broad. Four gates transverse-elliptical, half as high as broad. Ten to eleven pores on the half equator, fourteen to fifteen on the half meridian. Four conical radial spines, two on the poles of the lateral, two on the poles of the principal axis.
Dimensions.—Diameter of the central chamber 0.02; length of the lateral girdle 0.075, breadth 0.05; height of the gates 0.014, breadth 0.028.
Habitat.—North Pacific, Station 241, depth 2300 fathoms.
8. Trizonium hexabelonium, n. sp.
Central chamber elliptical. Lateral girdle hexagonal, one and a half times as long as broad. Four gates rhombic, two-thirds as high as broad. Eight to nine pores on the half equator, twelve to thirteen on the half meridian. Six radial spines in the lateral plane, opposite in pairs on the six corners of the lateral girdle (two principal and four diagonal).
Dimensions.—Length of the central chamber 0.024, breadth 0.018; length of the lateral girdle 0.06, breadth 0.04; height of the gates 0.02, breadth 0.03.
Habitat.—Pacific, central area, Station 263, depth 2650 fathoms.
9. Trizonium octobelonium, n. sp.
Central chamber elliptical. Lateral girdle hexagonal, one and one-third times as long as broad. Four gates kidney-shaped or nearly rhombic, twice as broad as high. Eleven to twelve pores on the half equator, sixteen to seventeen on the half meridian. Eight radial spines, opposite in pairs in two crossed diagonal planes. (An intermediate stage between Dizonium octacanthum and Amphipyle octostyle.)
Dimensions.—Length of the central chamber 0.03, breadth 0.024; length of the lateral girdle 0.09, breadth 0.07; height of the gates 0.025, breadth 0.05.
Habitat.—Indian Ocean, Madagascar, Rabbe, surface.
10. Trizonium decabelonium, n. sp.
Central chamber elliptical. Lateral girdle hexagonal, one and a half times as long as broad. Four gates rhombic, twice as broad as high. Twelve to thirteen pores on the half equator, seventeen to eighteen on the half meridian. Ten radial spines, two opposite on the two poles of the principal axis, eight others opposite in pairs in two crossed diagonal planes.
