Subgenus 4. Rhaphidosphæra, Haeckel, 1881, Prodromus, p. 450.
Definition.—Pores of the spherical shell irregular, of different size or form. Radial spines scattered at intervals, not at all the nodal-points.
21. Acanthosphæra echinoides, Haeckel.
Cyrtidosphæra echinoides, Haeckel, 1865, Zeitschr. f. wiss. Zool., xv. p. 367, Taf. xxvi. fig. 5.
Shell thin walled, with irregular polygonal or more roundish pores of very different size. Forty to fifty very large meshes, separated by rows of much smaller meshes. Radial spines forty to sixty, half as long as the shell radius, bristle-shaped, with conical bases.
Dimensions.—Diameter of the shell 0.13, larger pores 0.03, smaller 0.003; length of the spines 0.03.
Habitat.—Mediterranean (Nice), surface.
22. Acanthosphæra longispina, n. sp.
Shell thin walled, with irregular polygonal meshes, four to six times as broad as the bars; six to eight on the radius. Thirty to forty radial spines, three-sided prismatic, twice as broad as the bars, twice to three times as long as the diameter of the shell.
Dimensions.—Diameter of the shell 0.12 to 0.15, pores 0.012 to 0.02, bars 0.003; length of the radial spines 0.2 to 0.4, breadth 0.006.