Page:Scientific results HMS Challenger vol 18 part 1.djvu/437

Rh umbel composed of nine to twelve curved branches of equal length, which are again ramified and resemble the inflorescence of an umbelliferous plant, the distal ends of all ramules falling in a spherical face.

Dimensions.—Diameter of the shell 0.12, pores 0.006, bars 0.002; length of the spines 0.14, breadth 0.002.

Habitat.—South Atlantic, Station 325, surface.

Definition.—Pores of the shell irregular, of different size or form.

5. Elaphococcus dichotomus, n. sp.

Pores irregular, polygonal, twice to four times as broad as the bars; six to eight on the radius. Thirty to sixty radial spines cylindrical, curved, as long as the shell diameter, simply forked at the distal end; both branches one-third as long as the undivided part.

Dimensions.—Diameter of the shell 0.15, pores 0.007 to 0.015, bars 0.004; length of the spines 0.2, breadth 0.004.

Habitat.—Arctic Ocean, Greenland, surface (Koch).

6. Elaphococcus umbellatus, n. sp.

Pores irregular, roundish, or polygonal, twice to five times as broad as the bars; six to eight on the radius. Forty to sixty radial spines cylindrical, curved, as long as the shell radius, having at the distal end an irregular umbel, composed of six to twelve short branches, which are irregularly ramified or forked. (Differs from the regular Elaphococcus umbellifer mainly in the irregularity.)

Dimensions.—Diameter of the shell 0.14, pores 0.007 to 0.015, bars 0.003; length of the spines 0.12, breadth 0.01.

Habitat.—South-east Pacific (Juan Fernandez), Station 299, surface.

7. Elaphococcus drymodes, n. sp.

Pores irregular, roundish, little broader than the bars; ten to twelve on the radius. Eighty to one hundred and twenty (or more) radial spines, cylindrical, three to four times as long as the shell diameter, irregularly forked or repeatedly dichotomous (each spine with forty to sixty forked branches); the distal ends of all branches fall in a spherical plane. (Differs from the regular Elaphococcus cervicornis mainly in the irregularity.)

Dimensions.—Diameter of the shell 0.1, pores and bars 0.003 to 0.008; length of the spines 0.3 to 0.4, breadth 0.01.

Habitat.—Arctic Ocean, Iceland (Steenstrup).