Page:Scientific results HMS Challenger vol 18 part 2.djvu/785

Rh 1. Entocannula circularis, n. sp.

Shell circular or nearly circular, lenticular, strongly compressed. Pharynx cylindrical, one-third or one-fourth as broad as the shell, twice as broad as long, its outer and inner apertures of equal breadth. Surface smooth.

Dimensions.—Diameter of the shell 0.20 to 0.32, of the pharynx 0.07 to 0.09.

Habitat.—North Pacific, Station 250, depth 3050 fathoms.

2. Entocannula subglobosa, n. sp.

Challengeria bromleyi, (partim), John Murray, 1879, in schedulis Chall. Coll.

Shell circular, nearly spherical, slightly compressed. Pharynx funnel-shaped, truncate, conical, its outer opening twice as broad as the inner. Surface smooth.

Dimensions.—Diameter of the shell 0.25 to 0.28, of the inner mouth 0.05.

Habitat.—South Pacific, Station 289, depth 2550 fathoms.

3. Entocannula infundibulum, n. sp. (Pl. 99, fig. 19).

Challengeria bromleyi (partim), John Murray, 1879, in litteris, Narr. Chall. Exp., vol. i. p. 226, pl. A, fig. 5.

Shell ovate, truncate at the mouth, slightly compressed. Pharynx funnel-shaped, its outer aperture two to three times as broad as the inner. Surface smooth.

Dimensions.—Length of the shell 0.22 to 0.28, breadth 0.2 to 0.25; inner mouth 0.04 to 0.08.

Habitat.—South Atlantic, Station 318, depth 2040 fathoms.

4. Entocannula hirsuta, n. sp. (Pl. 99, fig. 20).

Trichogromia hirsuta, Haeckel, 1881, Manuscript.

Shell ovate. Pharynx cylindrical, one-fourth as broad as the shell, its inner and outer apertures of equal breadth. The whole surface of the shell, and mainly the outer mouth, is densely covered with thin, curved, siliceous bristles.

Dimensions.—Length of the shell 0.27 to 0.36, breadth 0.2 to 0.3; mouth 0.05 to 0.08.

Habitat.—North Atlantic, Færöe Channel (Gulf Stream), John Murray, depth 600 fathoms.

Definition.— with a pharynx, and with one or more teeth on the mouth, but without marginal spines.

The genus Pharyngella differs from the preceding Entocannula, its ancestral form, in the development of one or more teeth on the peristome, and exhibits therefore the same relation to it that Challengeria bears to Lithogromia. Only a few species of this genus have been observed, all in the Atlantic.