Page:Scientific results HMS Challenger vol 18 part 2.djvu/600

1476 Dimensions.—Length of the shell (with five joints) 0.12; length of the fifth joint 0.04, breadth 0.08.

Habitat.—Central Pacific, Station 268, depth 2900 fathoms.

Definition.— (vel Stichocyrtida eradiata aperta), with conical shell gradually dilated towards the wide open mouth. Cephalis without horn.

The genus Dictyomitra agrees with the preceding Lithostrobus in the slender, conical form of the multiarticulate shell, but differs from it in the absence of a horn on the cephalis; the horn is here completely lost.

Definition.—Shell smooth, with joints nearly equal in length.

1. Dictyomitra articulata, Haeckel.

Eucyrtidium articulatum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. xi. figs. 2, 3.

Shell slender, conical, smooth, with six to eight deep strictures. All joints nearly equal in length, gradually increasing in breadth, the eighth four times as broad as long, and twice as broad as the fourth joint. In each joint three to four transverse series of small, regular, circular pores.

Dimensions.—Length of the shell (with eight joints) 0.12, of each joint 0.015; breadth of the fourth joint 0.04, of the eighth joint 0.08.

Habitat.—Fossil in Barbados.

2. Dictyomitra macilenta, Haeckel.

Eucyrtidium macilentum, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 291, Taf. vii. fig. 15.

Shell slender, conical, smooth, with five to seven deep strictures. All joints nearly equal in length, gradually increasing in breadth, the sixth joint three times as broad as long, and twice as broad as the second. In each joint only two transverse series of small, regular, circular pores.

Dimensions.—Length of the shell (with seven joints) 0.08, of each joint 0.012; breadth of the sixth joint 0.036, of the second 0.018.

Habitat.—Western Tropical Pacific, Stations 200 to 225, in various depths.