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.