Page:Scientific results HMS Challenger vol 18 part 2.djvu/431

Rh roundish, double-contoured pores, irregularly disposed. Mouth constricted, two-thirds as broad as the thorax, with a broad, hyaline peristome.

Dimensions.—Cephalis 0.02 long, 0.03 broad; thorax 0.09 long, 0.06 broad.

Habitat.—East coast of Australia, Station 164, surface.

7. Dictyocephalus mediterraneus, n. sp. (Pl. 62, fig. 2).

Shell rough, thin-walled, with slight collar stricture. Length of the two joints = 3 : 10, breadth = 4 : 8. Cephalis hemispherical, with small, circular pores. Thorax ovate, truncate, with much larger circular pores of different sizes and thin bars between them. Mouth little constricted, two-thirds as broad as the thorax, with a narrow, hyaline peristome.

Dimensions.—Cephalis 0.03 long, 0.04 broad; thorax 0.1 long, 0.08 broad.

Habitat.—Mediterranean, Smyrna (Haeckel), surface.

8. Dictyocephalus papillosus, Haeckel.

Eucyrtidium papillosum, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 293, Taf. vii. fig. 10.

Shell thin-walled, papillate, with obliterated collar stricture. Length of the two joints = 2 : 7, breadth = 3 : 5. Cephalis hemispherical, with small, circular pores. Thorax slenderly ovate, with larger, subregular, circular pores, separated by oblique series of conical papillæ. Mouth with a broad, hyaline peristome (the "third articulus" of Ehrenberg), separated by a stricture from the little broader thorax.

Dimensions.—Cephalis 0.02 long, 0.03 broad; thorax 0.07 long, 0.05 broad.

Habitat.—Western Tropical Pacific (Philippine Sea), depth 3300 fathoms.

9. Dictyocephalus tabulatus, n. sp.

Shell thin-walled, papillate, with obliterated collar stricture. Length of the two joints = 2 : 10, breadth = 3 : 7. Cephalis hemispherical, with small, circular pores. Thorax slenderly ovate, truncate, with large, subregular, circular, hexagonally-framed pores. Mouth little constricted, nearly as broad as the thorax, with a broad, hyaline peristome.

Dimensions.—Cephalis 0.02 long, 0.03 broad, thorax 0.1 long, 0.07 broad.

Habitat.—Central Pacific, Station 271, depth 2425 fathoms.

10. Dictyocephalus reticulum, Haeckel.

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

Eucyrtidium reticulum, Ehrenberg, 1861, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 300.

Shell thin-walled, smooth, with deep collar stricture. Length of the two joints = 2 : 8, breadth = 3 : 5. Cephalis subspherical, with small, circular pores. Thorax campanulate, with