Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, Second Part: Subclass Osculosa; Index / Report on the Scientific Results of the Voyage of H.M.S. Challenger During the Years 1873-76, Vol. XVIII

by Ernst Haeckel

Definition.—Basal plate with two large collar pores only, separated by the base of the primary ring.

1. Petalospyris foveolata, Ehrenberg.

Petalospyris foveolata, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig. 14; Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, p. 80, Taf. xxii. fig. 10.

Shell campanulate, smooth, with distinct sagittal stricture and subregular circular pores. Basal plate with two large collar pores only. Apical horn and the eight feet slender, conical, slightly curved, about as long as the shell; feet somewhat divergent (often seven or nine instead of eight).

Dimensions.—Shell diameter 0.04 to 0.05; length of the horn and the feet 0.04 to 0.05.

Habitat.—Fossil in Barbados.

2. Petalospyris floscula, n. sp.

Shell nut-shaped, tuberculate, with deep sagittal stricture and subregular circular pores. Basal plate with two large triangular pores only. Apical horn slender, conical, twice as long as the shell. Twelve to sixteen feet flattened, leaf-shaped, broad, slightly divergent, as long as the shell, with truncate distal end.

Dimensions.—Shell 0.06 long, 0.09 broad; horn 0.12 long, feet 0.05 to 0.07 long.

Habitat.—Central Pacific, Station 266, depth 2750 fathoms.