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

Dimensions.—Cephalis 0.03 long, 0.03 broad; thorax 0.04 long, 0.04 broad.

Habitat.—North Atlantic, Station 354, surface; Canary Islands and Azores.

3. Sethopera pyrum, Haeckel.

? Lithopera pyrum, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 297.

Cephalis hemispherical, with a small conical horn of half the length. Length of the two joints = 3 : 10, breadth = 3 : 7. Thorax pear-shaped, with rather large, regular, quincuncial pores; its upper half with three divergent ribs in the wall, half as broad as the subspherical lower half. (The three ribs probably were overlooked by Ehrenberg.)

Dimensions.—Cephalis 0.03 long, 0.03 broad; thorax 0.1 long, 0.07 broad.

Habitat.—North Pacific, Station 256, surface; Californian Sea, 2600 fathoms, Ehrenberg.

4. Sethopera lagena, Haeckel.

Lithopera lagena, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. iii. fig. 4.

Cephalis pear-shaped, with a small conical horn of half the length. Length of the two joints = 3 : 8, breadth = 3 : 6. Thorax smooth, pear-shaped, with irregular roundish pores; in the wall of its upper third three divergent thin ribs (sometimes wanting); the lower half inflated. (Compare Sethocapsa lagena.)