Page:Scientific results HMS Challenger vol 18 part 1.djvu/919

Rh

Definition.—Spongy cortical shell immediately enclosing the lentelliptical medullary shell, without hollow interval.

1. Spongophortis spongiosa, n. sp.

Cortical shell irregular, roundish, rough or tuberous, composed of loose spongy framework, which immediately envelops the lentelliptical central Larnacilla-shell; the diameter of the former becomes about five to six times as large as that of the latter.

Dimensions.—Diameter of the spongy cortical shell 0.15 to 0.25, of the trizonal medullary shell 0.03 to 0.04.

Habitat.—Pacific, central area, Station 274, surface.

Definition.—Spongy cortical shell separated by a hollow interval from the lentelliptical medullary shell.

2. Spongophortis radiosa, n. sp.

Cortical shell irregular, roundish, four to five times as large as the enclosed lentelliptical Larnacilla-shell, with which it is connected by ten to twenty irregularly disposed radial beams. Spongy framework compact, about as thick as the medullary shell. Surface covered with numerous short, bristle-shaped, radial spines.

Dimensions.—Diameter of the spongy cortical shell 0.15 to 0.2, of the trizonal medullary shell 0.035 to 0.045.

Habitat.—South Atlantic, Station 332, depth 2200 fathoms.

3. Spongophortis larnacilla, n. sp. (Pl. 49, figs. 11a-11d).

Cortical shell irregular, roundish, tuberous, three to four times as large as the enclosed lentelliptical Larnacilla-shell, connected with it by two opposite latticed wings (the halves of the transverse girdle of Tetrapyle). Spongy framework compact, about half as thick as the medullary shell. Surface rough. (May be regarded as an abnormal Tetrapyle or Larnacalpis, with an irregular spongy cortical shell.)

Dimensions.—Diameter of the spongy cortical shell 0.16 to 0.2, of the trizonal medullary shell 0.04 to 0.06.

Habitat.—Pacific, central area, Station 271, depth 2425 fathoms.