Page:Scientific results HMS Challenger vol 18 part 1.djvu/995

Rh Dimensions.—Length of the two major spines 0.1 to 0.2, breadth 0.02 to 0.03; length of the eighteen minor spines 0.05 to 0.1.

Habitat.—Central Pacific, Stations 270 to 274, surface.

14. Amphilonche violina, n. sp. (Pl. 132, fig. 5).

Two principal spines quadrangular prismatic, nearly violin-shaped, with four very broad, prominent, lamellar wings, which are constricted in the middle part, and broadened towards the two ends; apex truncate pyramidal; base with a large leaf-cross. Eighteen smaller spines much shorter, of equal breadth at the base, assuming the form of a quadrangular pyramid, thin prismatic in the distal half. Central capsule spindle-shaped, opaque.

Dimensions.—Length of the two major spines 0.15 to 0.18, breadth 0.02 to 0.025; length of the eighteen minor spines 0.04 to 0.08.

Habitat.—Central Pacific, Station 271, surface.

15. Amphilonche tetraptera, Haeckel.

Amphilonche tetraptera, Haeckel, 1862, Monogr. d. Radiol., p. 391, Taf. xvi. fig. 5, Taf. xviii. fig. 20.

Acanthometra tetraptera, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 808.

Two principal spines four-sided pyramidal, with four broad lamellar prominent edges; apex simple or bifid; base with a large leaf-cross. Eighteen smaller spines of similar form, but only half as large. Central capsule spherical, opaque.

Dimensions.—Length of the two major spines 0.2, breadth on the base 0.025; length of the eighteen minor spines 0.1.

Habitat.—Mediterranean (Messina); North Atlantic, Canary Islands, Stations 352 to 354, surface.

Definition.—Spines in the basal part grown together, so that the whole skeleton represents a single piece of acanthin; a star with two larger and eighteen smaller rays.

16. Amphilonche concreta, n. sp. (Pl. 132, figs. 4, 4a).

Two principal spines cylindrical, very long, of equal breadth throughout their whole length, with simple conical apex. Eighteen smaller spines short, conical or bristle-shaped, scarcely one-fourth or one-tenth as long, often quite rudimentary. All twenty spines perfectly grown together in the centre, forming a single piece of acanthin (derived from Amphilonche belonoides by central concrescence; often the sutures of the concreted bases are visible, fig. 4a).

Dimensions.—Length of the two major spines 0.1 to 0.4, breadth 0.005 to 0.015; length of the eighteen minor spines 0.005 to 0.15.

Habitat.—Cosmopolitan; Mediterranean, Atlantic, Pacific, surface.