3. Coronosphæra convolvulus, n. sp.
Shell irregular roundish, with a variable number (five to ten) of long, curved tubules, about as long as the shell diameter. The inner half of the tubuli is narrow, cylindrical; the outer half funnel-like dilated, similar to the flower of Convolvulus. The outer aperture is elegantly dentated, five to six times as broad as the inner aperture. Pores of the shell and of the tubuli very irregular roundish, about as broad as the bars.
Dimensions.—Diameter of the shell 0.08 to 0.09, of the pores and bars 0.004 to 0.008; length of the tubuli 0.07 to 0.1, inner aperture 0.01, outer aperture 0.05.
Habitat.—Tropical Atlantic, Station 347, surface.
Subfamily Clathrosphærida, Haeckel, 1881, Prodromus, p. 472.
Definition.—Collosphærida with a double lattice-shell around every central capsule of the cœnobium; both concentric shells connected by irregular or subradial beams, commonly solid or lamellar staffs, rarely hollow tubes.
Genus 43. Clathrosphæra,[[65]] Haeckel, 1881, Prodromus, p. 472.
Definition.—Collosphærida with a double lattice-shell around every central capsule of the cœnobium; surface of the outer shell smooth.
The genus Clathrosphæra (with smooth surface) and the following Xanthiosphæra (with spiny surface) form together the small subfamily, Clathrosphærida, different from the other Collosphærida by the double lattice-shell. From the surface of the inner primary shell arise either solid spines or hollow tubes, which unite by the anastomosis of irregular branches and so form the outer secondary shell, often very incomplete and irregular. All Clathrosphærida seem to inhabit great depths.