2. Tessarastrum spinozæ, n. sp.
Cross rectangular. Both principal arms of equal size and form, ten times as long as broad, and twice as long as the lateral arms, which are only five times as long as broad. All arms linear, at their distal end club-shaped, and armed with twenty to thirty very strong angular spines. Patagium incomplete, enveloping only the basal half of the arms. (Resembles Histiastrum boseanum, Pl. [46], fig. 1, but differs in the broader arms and the unequal size of both pairs.) I call this species after the great monistic philosopher Benedictus Spinoza.
Dimensions.—Radius of the principal arms 0.3, of the lateral arms 0.16; basal breadth 0.025, distal breadth 0.05.
Habitat.—South Atlantic, Station 333, surface.
3. Tessarastrum brunonis, n. sp. (Pl. [45], fig. 9).
Histiastrum brunonis, Haeckel, 1881, Prodromus et Atlas (pl. xlv. fig. 9).
Cross rectangular. Both principal arms of equal size and form, three times as long as broad, each with ten joints, three times as long as the lateral arms, which are nearly square, with four joints. All arms rounded, at their truncated end little broader than at their base. No spines. Patagium complete, envelops the whole shell, and is composed of two parallel lattice-lamellæ on each side of the flat disk, which are connected by very fine perpendicular bars. This is shown clearly in fig. 9, Pl. [45], where the disk is seen from the edge. I call this species after the great Italian philosopher Giordano Bruno.
Dimensions.—Radius of the principal arms 0.22, of the lateral arms 0.12; basal breadth 0.04, distal breadth 0.05.
Habitat.—South Pacific, Station 285, depth 2375 fathoms.