Subgenus 2. Saturnalium, Haeckel.
Definition.—Ring armed on the periphery with numerous spines or thorns.
5. Saturnalis trochoides, n. sp.
Haliomma species, Bury, 1862, Polycystins of Barbados, pl. xx. fig. 2.
Pores of the spherical shell subregular, circular, twice as broad as the bars. Twelve to sixteen pores on the half equator. Ring circular, armed with ten to twelve strong conical, irregular spines, its diameter twice as great as that of the sphere.
Dimensions.—Diameter of the sphere 0.08, pores 0.006, bars 0.003; diameter of the circular ring 0.16; length of the radial spines 0.02 to 0.04; thickness of the ring and the axial beams 0.01.
Habitat.—Fossil in the Barbados rocks.
6. Saturnalis rotula, n. sp. (Pl. [13], fig. 15).
Pores of the spherical shell regular, circular, twice as broad as the bars; sixteen to twenty on the half equator. Ring circular, armed with fifteen to twenty strong, conical, irregular spines, partly simple, partly divided into two or three irregular branches; diameter of the ring two and a half times as great as that of the sphere.
Dimensions.—Diameter of the sphere 0.08, pores 0.004, bars 0.002; diameter of the circular ring 0.2, length of its spines 0.02 to 0.03; thickness of the ring and the radial beams 0.01.