6. Arachnosphæra velaris, n. sp.
Innermost shell with irregular, polygonal meshes; its diameter twice as long as the distance between it and the second shell, quite as long as the distance between the third and fourth shells; the distance between the concentric shells gradually increasing from the centre. Radial spines twenty to thirty, each with ten to twelve verticils.
Dimensions.—Diameter of the innermost shell (A) 0.5; distances of the following shells—A, B = 0.025, B, C = 0.037, C, D = 0.05, D, E = 0.062, E, F = 0.075.
Habitat.—Tropical Atlantic, Station 347, surface.
Subfamily Spongiommida,[[149]] Haeckel.
Definition.—Astrosphærida with spongy spherical or polyhedral shell (with or without enclosed concentric lattice-shells).
Genus 111. Spongiomma,[[150]] n. gen.
Definition.—Astrosphærida with solid spongy sphere, with numerous simple radial spines, but without latticed medullary shells.
The genus Spongiomma differs from its ancestral form, Styptosphæra, in the development of simple radial spines on the surface of the solid sphere, the entire mass of which is composed of an irregular, spongy wicker-work.