Definition.—Stylosphærida with three concentric lattice-spheres and two equal opposite spines, connected at the distal end by a circular or elliptical ring.
The genus Saturninus differs from the similar Saturnulus by the triplication of the spherical lattice-shell; the inner shell is enclosed in the central capsule, whilst both the others lie outside it.
1. Saturninus triplex, n. sp.
Radial proportion of the three spheres = 4 : 3 : 1. Inner cortical shell with regular, circular pores, of the same breadth as the bars, sixteen to eighteen on the half equator; outer cortical shell connected with the inner by numerous bristle-like radial spines, network very delicate, cobweb-shaped, with irregular polygonal meshes. Ring elliptical, two and a half times as broad as the outer shell.
Dimensions.—Diameter of the inner sphere 0.03, middle 0.09, outer 0.12; pores and bars of the middle shell 0.004; major axis of the elliptical ring 0.3, minor 0.25; thickness of the ring and the axial beams 0.008.
Habitat.—Central Pacific, Station 272, surface.
Subfamily Cromyostylida, Haeckel, 1881, Prodromus, pp. 449, 453.
Definition.—Stylosphærida with four concentric spherical lattice-shells (two medullary and two cortical).
Genus 54. Stylocromyum,[[77]] Haeckel, 1881, Prodromus, p. 453.
Definition.—Stylosphærida with four concentric lattice-spheres and two free spines of equal size and similar form.