Page:Scientific results HMS Challenger vol 18 part 2.djvu/41

Rh 2. Plagonium lampoxanthium, n. sp.

Spines irregularly curved, slender, cylindrical, six to eight times as long as the common middle rod, in the proximal half smooth, in the distal half covered with short thorns. (Similar to an isolated spiculum of Lampoxanthium punctatum or of Sphærozoum variabile, Pl. 4, fig. 5.)

Dimensions.—Length of the spines 0.18, of the middle rod 0.03.

Habitat.—North Pacific, Station 240, surface.

3. Plagonium arborescens, n. sp.

Spines irregularly curved and branched, slender, cylindrical, thorny, twelve to sixteen times as long as the middle rod; the branches are large, arborescent, their ramules again ramified and very thorny.

Dimensions.—Length of the spines 0.2 to 0.25, of the middle rod 0.02.

Habitat.—Indian Ocean, Madagascar (Rabbe), surface.

4. Plagonium trigeminum, n. sp.

Spines straight, slender, cylindrical, four to six times as long as the middle rod, in the basal half smooth, in the distal half arborescent, with three to four irregular verticils of ramified branches. (Similar to a single spiculum of Sphærozoum verticillatum, Pl. 4, fig. 7.)

Dimensions.—Length of the spines 0.15 to 0.2, of the middle rod 0.05.

Habitat.—Central Pacific, Station 265, depth 2900 fathoms.

5. Plagonium distriactis, n. sp.

Spines straight and stout, three-sided prismatic, smooth, ten to twelve times as long as the middle rod; each on the distal end cleft into three divergent straight branches, which are again trichotomous.

Dimensions.—Length of the spines 0.15 to 0.18, of the middle rod 0.015.

Habitat.—South Pacific, Station 288, surface.

Definition.— with numerous (seven to nine or more) radial spines.

Definition.— with numerous (seven to nine or more) radial spines, arising from a common centre and lying in different planes.