Page:Scientific results HMS Challenger vol 18 part 2.djvu/241

Rh 4. Botryocella quadricellaris, n. sp. (Pl. 96, fig. 13).

Cephalis quadrilobate; the helmet-shaped occipital lobe twice as long as the two paired subspherical buccal lobes, and three times as long as the odd spherical frontal lobe. Thorax nearly spherical, about as long as the cephalis.

Dimensions.—Length of the shell 0.1, breadth 0.05.

Habitat.—Central Pacific, Station 272, depth 4475 fathoms.

5. Botryocella quadrigemina, n. sp. (Pl. 96, fig. 14).

Cephalis quadrilobate, with two pairs of lateral ovate lobes and complete sagittal constriction; the two occipital lobes nearly twice as large as the two frontal lobes. Thorax ovate, separated from the cephalis by a collar septum with four cortinar pores (fig. 14).

Dimensions.—Length of the shell 0.09, breadth 0.06.

Habitat.—Indian Ocean, Sunda Strait (Rabbe), surface.

6. Botryocella multicellaris, n. sp. (Pl. 96, fig. 12).

Cephalis multilobate; occipital lobe helmet-shaped, very large, about twice as long and broad as the frontal half of the shell, which is divided into six to eight small roundish clustered lobes. Thorax subspherical, of about the same size as the cephalis.

Dimensions.—Length of the shell 0.1, breadth 0.05.

Habitat.—South Pacific Station 297, depth 1775 fathoms.

Definition.— with tubes on the cephalis, and with the mouth of the thorax closed.

The genus Lithobotrys, the oldest and first known of the, was founded by Ehrenberg in 1844, and was one of his five oldest genera of Polycystina. It represented by itself the suborder until the year 1860. The numerous species described by Ehrenberg belong to very different genera of, and partly also of. Following Bütschli (1882) we retain here the name Lithobotrys for those species, the type of which is Lithobotrys geminata. The genus Lithocorythium of Ehrenberg is for the greater part identical with it. When in the preceding genus Acrobotrys the mouth of the thorax becomes closed by lattice work, Lithobotrys arises. In the latter as well as in the former the number of tubes on the cephalis is different, and may characterise different subgenera.