Page:Scientific results HMS Challenger vol 18 part 2.djvu/430

1306 3. Dictyocephalus excellens, Haeckel.

Eucyrtidium excellens, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. x. fig. 2.

Shell annulate, thick-walled, urceolate, with slight collar stricture. Length of the two joints = 5 : 10, breadth = 4 : 7. Cephalis large, ovate-conical, with numerous oblique pore-canals. Thorax ovate, with ten to twelve transverse rows of regular, roundish pores, which are separated by prominent annular ribs. Mouth constricted, about half as broad as the thorax, with a broad hyaline peristome.

Dimensions.—Cephalis 0.05 long, 0.04 broad; thorax 0.1 long, 0.07 broad.

Habitat.—Fossil in Barbados.

4. Dictyocephalus ocellatus, Haeckel.

Dictyocephalus ocellatus, Haeckel, 1862, Monogr. d. Radiol., p. 297.

? Eucyrtidium ocellatum, Ehrenberg, 1861, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 299.

Shell smooth, thick-walled, with deep collar stricture. Length of the two joints = 3 : 9, breadth = 4 : 7. Cephalis subspherical, with numerous oblique pore-canals. Thorax inflate, campanulate, hyaline, only with three or four remote transverse rows of circular, double-contoured pores of equal size. Mouth constricted, one-third as broad as the thorax, with a narrow hyaline annular peristome.

Dimensions.—Cephalis 0.03 long, 0.04 broad; thorax 0.09 long, 0.07 broad.

Habitat.—North Atlantic, Greenland; Færöe Channel (Gulf Stream), John Murray.

5. Dictyocephalus crassiceps, Haeckel.

Eucyrtidium crassiceps, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. xi. fig. 4.

Shell smooth, thick-walled, with sharp collar stricture. Length of the two joints = 4 : 6, breadth = 3 : 4. Cephalis ovate, in the upper part with scattered pores, in the lower part with one transverse row of pores. Thorax hyaline, subcylindrical, only with four or five remote transverse rows of small, circular pores. Mouth constricted, half as broad as the thorax, with a short hyaline peristome.

Dimensions.—Cephalis 0.04 long, 0.03 broad; thorax 0.06 long, 0.04 broad.

Habitat.—Fossil in Barbados.

6. Dictyocephalus australis, n. sp. (Pl. 62, fig. 1).

Shell smooth, thick-walled, with slight collar stricture. Length of the two joints = 2 : 9, breadth = 3 : 6. Cephalis hemispherical, with few small pores. Thorax subcylindrical, with large,