Arms at different distances, club-shaped, about twice as long as broad, and smaller than the large triangular central disk. Both paired arms smaller and more approximate than the opposite odd arm. Patagium incomplete, enveloping only the basal half of the arms as a circular spongy disk of loose framework.
Dimensions.—Radius of the arms 0.18, basal breadth 0.05, distal breadth 0.08.
Habitat.—Fossil in the Tertiary rocks of Sicily, Grotte, Stöhr.
8. Dictyocoryne echinata, n. sp.
Arms unequal and at different distances, club-shaped, in the distal half twice as broad as in the basal half, three times as long as the small triangular central disk, at their distal end armed with one larger and several smaller conical spines. Both paired arms with touching bases, and only half as large as the doubly remote odd arm. Patagium incomplete, enveloping only the basal half of the arms, and forming a circular disk of looser framework. Surface thorny.
Dimensions.—Radius of the arms 0.15 to 0.2, basal breadth 0.03, distal breadth 0.06.
Habitat.—South Atlantic, Station 325, surface.
Genus 264. Spongasteriscus,[[303]] Haeckel, 1862, Monogr. d. Radiol., p. 474 (sensu restricto).
Definition.—Spongodiscida with four spongy arms on the margin of the circular or quadrangular disk, crossed in two equatorial diameters, without a connecting patagium.
The genus Spongasteriscus (in the restricted definition here stated) exhibits on the margin of the disk four spongy arms, which form either a regular or a bilateral cross. It corresponds to Stauralastrum and Myelastrum among the Porodiscida, to Astractura among the Coccodiscida.