Disk circular with spiny margin, three times as broad as the triangular, Triopyle-shaped medullary shell. Three gates of the cortical shell kidney-shaped, on the inside with an interradial spine, twice as broad as the three pentagonal arms. Chambered equatorial girdle with twenty-four subregular chambers, in the radius of one odd gate with a large marginal osculum, which is as broad as the medullary shell, and surrounded by a dense corona of twenty to thirty strong conical spines.
Dimensions.—Diameter of the disk 0.15, of the cortical shell 0.1, of the medullary shell 0.05, of the marginal osculum 0.06.
Habitat.—Central Pacific, Station 272, depth 2600 fathoms.
2. Discopyle elliptica, n. sp. (Pl. [48], fig. 20).
Disk elliptical, four-fifths as broad as long, with spiny margin, three times as broad as the triangular, Triopyle-shaped medullary shell. Three gates of the cortical shell roundish, on the inside with an interradial spine, little broader than the quadrangular arms. Chambered equatorial girdle with twenty to thirty irregular chambers, on one pole of the main axis with a large marginal osculum, which is one-third as broad as the length of the main axis, and armed with a corona of twenty to thirty short conical spines. The osculum does not correspond to a certain radius.
Dimensions.—Diameter of the disk 0.15, of the cortical shell 0.08, of the medullary shell 0.04, of the marginal osculum 0.05.
Habitat.—Central Pacific, Station 267, depth 2700 fathoms.
Family XXIII. Spongodiscida, Haeckel (Pl. [41], fig. 11).
Spongodiscida et Spongocyclida, Haeckel, 1862, Monogr. d. Radiol.,
pp. 452, 460, 469.