Page:Scientific results HMS Challenger vol 18 part 2.djvu/240

1116 anterior sternal from the nasal lobe. Two paired lateral tubes arise from the base of two ovate frontal lobes. The five tubes correspond in disposition to the five spines of Stephanium. Thorax truncate. Pores small.

Dimensions.—Length of the shell 0.12, breadth 0.09.

Habitat.—Tropical Atlantic, Station 347, depth 2250 fathoms.

Definition.— without tubes on the cephalis, and with the mouth of the thorax closed.

The genus Botryocella differs from the closely allied Botryopyle in having the mouth of the thorax closed, and may be derived from it by development of a lattice-plate, effecting this closure. It bears therefore the same relation to the latter that Dicolocapsa has to Dictyocephalus.

1. Botryocella nucula, Haeckel.

Lithobotrys nucula, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 76, Taf. iii. fig. 16.

Lithobotrys adspersa, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 76, Taf. iii. fig. 15.

Cephalis trilobate; occipital lobe helmet-shaped, nearly twice as long as the two ovate frontal lobes. Thorax about as long as the cephalis. Pores very small and scarce.

Dimensions.—Length of the shell 0.06, breadth 0.03.

Habitat.—Fossil in Barbados.

2. Botryocella borealis, Haeckel.

Lithobotrys borealis, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 294, Taf. ii. fig. 3.

Cephalis trilobate; occipital lobe ovate, little longer than the two ovate frontal lobes. Thorax about twice as long as the cephalis. Pores very numerous and small.

Dimensions.—Length of the shell 0.08, breadth 0.04.

Habitat.—North Atlantic, Greenland, depth 1000 to 2000 fathoms.

3. Botryocella tricellaris, n. sp.

Cephalis trilobate, with three odd sagittal lobes; the middle or central lobe larger than the anterior frontal and smaller than the posterior occipital lobe. Thorax nearly spherical, about as long as the cephalis. Pores small and scarce.

Dimensions.—Length of the shell 0.08, breadth 0.06.

Habitat.—North Atlantic, Station 353, depth 2965 fathoms.