Page:Scientific results HMS Challenger vol 18 part 2.djvu/271

Rh simple collar-holes. The apical horn and the three feet are three-sided prismatic, smooth, about twice as long as the columella, straight and widely divergent.

Dimensions.—Shell 0.08 long, 0.1 broad.

Habitat.—Tropical Pacific, Station 225, depth 4475 fathoms.

3. Euscenium hemisphæricum, n. sp.

Shell hemispherical smooth, half as long as broad, with small and numerous subregular circular pores. Basal plate with three large triangular simple collar-holes. Horn slender, three-sided prismatic, twice as long as the columella. Feet very slender, with three denticulate edges, widely divergent and curved like the quadrant of a circle.

Dimensions.—Shell 0.04 long, 0.06 broad.

Habitat.—North Pacific, Station 244, depth 2900 fathoms.

4. Euscenium tricolpium, n. sp. (Pl. 53, fig. 12).

Archiscenium tricolpium, Haeckel, 1881, Prodromus et Atlas, ''loc. cit.''

Shell cap-shaped, nearly hemispherical, with three vaulted hemispherical bosoms between the three arches ascending from the feet to the horn. Network very irregular, with polygonal meshes, of different form and size. Basal plate with three large primary and some smaller irregular accessory collar-holes. Horn slender, straight, twice as long as the columella. Feet of the same length, slender, widely divergent, slightly curved. The three edges of the horn and the feet are elegantly denticulated.

Dimensions.—Shell 0.04 long, 0.08 broad.

Habitat.—Central Pacific, Station 266, depth 2750 fathoms.

5. Euscenium tripospyris, n. sp. (Pl. 84, fig. 8).

Tripospyris euscenium, Haeckel, 1881, Prodromus et Atlas.

Shell nearly spherical, smooth, with numerous small circular pores. Basal plate also with numerous small pores. Horn and feet stout, three-sided prismatic, straight or slightly curved, about as long as the thin, somewhat curved columella. This species is closely allied to Tripospyris.

Dimensions.—Shell 0.11 to 0.12 diameter, horn and feet 0.08 to 0.1 long.

Habitat.—South Pacific, Station 298, depth 2225 fathoms.

Definition.—Feet forked or branched.

6. Euscenium furcatum, n. sp.

Shell campanulate, smooth, with numerous irregular roundish pores. Basal plate with nine pores (three larger central and six smaller distal). Horn club-shaped, half as long as the columella.