Page:Scientific results HMS Challenger vol 18 part 2.djvu/535

Rh 3. Lophocyrtis synapta, n. sp. Pl. 68, fig. 15.

Shell spiny, with two sharp strictures. Length of the three joints = 5 : 10 : 6, breadth = 4 : 9 : 7. Cephalis large, ovate, with numerous (twenty to thirty or more) conical, radially divergent spines of different sizes, the largest about as long as the cephalis. Thorax subconical, with numerous short, conical, divergent spines, which are directed downwards. Abdomen smooth, cylindrical. The irregular, polygonal pores are separated by thin bars, and in the thorax are twice to four times as broad as in the first and last joints.

Dimensions.—Length of the three joints, a 0.05, b 0.1, c 0.06; breadth, a 0.04, b 0.09, c 0.07.

Habitat.—Indian Ocean, Maldive Islands (Haeckel), surface.

4. Lophocyrtis coronata, Haeckel.

Eucyrtidium coronatum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. x. fig. 9.

Shell smooth, cylindrical, with two deep strictures. Length of the three joints = 4 : 3 : 4, breadth = 4 : 5 : 4. Cephalis subspherical, large, of about the same size and form as the thorax, with a coronal of four to eight short, conical spines on the apex. Pores in the two first joints irregular, roundish, twice to four times as broad as the small, circular pores of the cylindrical abdomen, which are disposed in four to eight transverse rows.

Dimensions.—Length of the three joints, a 0.04, b 0.03, c 0.04; breadth, a 0.04, b 0.05, c 0.04.

Habitat.—Central Pacific, Station 273, depth 2350 fathoms; fossil in Barbados.

5. Lophocyrtis biaurita, Haeckel.

Eucyrtidium biauritum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. x. fig. 8.

Eucyrtidium biauritum, Bütschli, 1882, Zeitschr. f. wiss. Zool., p. 540, Taf. xxxiii. fig. 38, a-f.

Shell smooth, with two distinct strictures. Length of the three joints = 1 : 6 : 3, breadth = 2 : 5 : 4. Cephalis small, hemispherical, hyaline, with two large, divergent, curved horns of three times the length. Thorax ovate, with few small, widely scattered pores. Abdomen cylindrical, without pores.

Dimensions.—Length of the three joints, a 0.015, b 0.06, c 0.03; breadth, a 0.02, b 0.05, c 0.04.

Habitat.—Fossil in Barbados.

Definition.— (vel Tricyrtida eradiata aperta), with cylindrical abdomen, and wide open truncate mouth. Cephalis without horn.

The genus Tricolocampe differs from its ancestral genus, Theocyrtis, in the loss of the cephalic horn; it has the same cylindrical form of the slender abdomen, and a wide