4. Acrosphæra spinosa, Haeckel.
Collosphæra spinosa, Haeckel, 1862, Monogr. d. Radiol., p. 536, Taf. xxxiv. figs. 12, 13.
Collosphæra spinosa, Cienkowsky, 1871, Archiv f. mikrosk. Anat., vii. p. 374, Taf. xxix. figs. 7-17.
Shell a regular or subregular sphere, covered with numerous, obliquely standing spines, irregularly scattered over the surface. In the half meridian of the shell fifteen to twenty irregular roundish pores of very different form and size, one to four times as broad as their bars. Spines conical, irregularly diverging and curved, their hollow base perforated by several pores, not longer than the diameter of the largest pores.
Dimensions.—Diameter of the shell 0.1 to 0.2, of the pores 0.001 to 0.04; length of the spines 0.01 to 0.02.
Habitat.—Mediterranean, Messina; Canary Islands, Haeckel.
5. Acrosphæra collina, n. sp. (Pl. [8], fig. 2).
Shell quite irregular, polyhedrical, hilly, with a variable number (eight to sixteen) of large conical hill-like prominences; every cone or hill about as high as broad, perforated by the same pores as the shell, on its top bearing a larger irregular roundish pore, and on its edge one single bristle-like spine, not larger than the diameter of this pore, obliquely inserted. In the half meridian of the shell twenty to thirty irregular roundish pores of very different size, one to six times as broad as the bars. A very characteristic species, closely resembling the following Odontosphæra.
Dimensions.—Diameter of the shell 0.15 to 0.25, of the pores 0.005 to 0.02; length of the spines 0.01 to 0.02, height of the hills from which they rise 0.03 to 0.04.
Habitat.—North coast of New Guinea, Station 218, surface.