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

5. Sethocyrtis subacuta, Haeckel.

Eucyrtidium subacutum, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 293, Taf. vii. fig. 18.

Shell smooth, pear-shaped, with sharp collar stricture. Length of the two joints = 1 : 4, breadth = 1 : 3. Cephalis subspherical, with small, irregular pores and a rudimentary horn of half the length. Thorax ovate, with large, subregular, hexagonal pores and thin bars between them. Mouth constricted, flat, half as broad as the thorax, without prominent peristome.

Dimensions.—Cephalis 0.02 long, 0.02 broad; thorax 0.08 long, 0.06 broad.

Habitat.—Philippine Sea, depth 3300 fathoms (Ehrenberg).

6. Sethocyrtis pleuracantha, Haeckel.

Eucyrtidium pleuracanthum, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 293, Taf. vii. fig. 21.

Shell smooth, bottle-shaped, with distinct collar stricture. Length of the two joints = 2 : 4, breadth = 1 : 3. Cephalis slenderly ovate, with an excentric pyramidal horn of the same length. Thorax inflate, ovate, with irregular, roundish pores and thin bars between them. Mouth constricted, flat, half as broad as the thorax, without prominent peristome.

Dimensions.—Cephalis 0.04 long, 0.02 broad; thorax 0.08 long, 0.06 broad.

Habitat.—Tropical Pacific, Stations 200, 225, 266, 274, &c., at various depths.