Radial tubes without inflated terminal knob, with a variable number of unequal terminal branches, which are constantly simple, never forked; the usual number is in the majority of the tubes three or four, often also two, rarely five to eight. Proximal whorl irregular, with a variable number of lateral branches (usually four to six).
Dimensions.—Length of the tubes 2.0 to 3.0, breadth 0.03 to 0.06; branches 0.1 to 0.3.
Habitat.—Central Pacific, Stations 271 to 274, depth 2350 to 2750 fathoms.
Genus 670. Aulodendron,[[288]] n. gen.
Definition.—Aulacanthida with a veil of tangential needles, and with radial tubes, which bear numerous, irregularly scattered, lateral and terminal branches.
The genus Aulodendron differs from the other Aulacanthida in the possession of lateral and terminal branches, which are irregularly scattered on the radial tubes and not arranged in regular verticils. The branches are usually short, simple or forked, rarely longer and again irregularly ramified.
1. Aulodendron antarcticum, n. sp. (Pl. [105], fig. 5).
Radial tubes cylindrical, more or less curved, in the inner proximal half smooth and half as broad as in the outer distal half, which is studded with irregularly curved, partly branched spines, arising usually perpendicularly from the tube. The majority of the spines usually simple, the minority forked, with two to four short branches, the largest spines scarcely twice as long as the breadth of the tube.
Dimensions.—Length of the tubes 0.7 to 0.9, breadth 0.01 to 0.02; length of the branches 0.02 to 0.04.
Habitat.—Antarctic Ocean (Kerguelen), Stations 156 to 159, surface.