Deep-Sea Echinoderms of New Zealand
Brisingenes Fisher, 1917
Brisingenes Fisher, 1917
Papulae on the disc restricted to a ring about the margin, two papulae opposite the base of each arm.
The genus was founded to accommodate two species known only from the page 18Buton Strait, Celebes, at a depth of 559 fathoms (Albatross Station 5648). Its occurrence in New Zealand waters is therefore of considerable interest.
Brisingenes delli sp. nov. Plate 3, Figs. D, F, H, holotype arm, paratype disc.
Description: Disc covered with fine, conical, sharp granules about 20 to the square millimetre. Margin of disc rounded. Madreporite conspicuous, marginal, on a raised plate. Anus central surrounded by about 10 small spinules, twice as large as the granules of the disc. Rays 14, long (at least 200 mm in the holotype, paratype disc 25 mm in diameter). The genital region swollen, occupying about 30 mm of the arm's length, beginning about 30 mm from the base. Costae 15–17, of overlapping rectangular plates each carrying 2 or 3 triangular pointed granules. Proximal adambulacral plates about as broad as long, carrying 2 proximal furrow-spines, one proximal accessory subambulacral spine, one distal furrow-spine, and one primary subambulacral spine on the distal half of the plate. Occasionally the accessory subambulacral enters the furrow, making three proximal furrow-spines. The typical arrangement at the base of the arm is, by Fisher's formula (Fisher, 1919, p. 510):
Further out on the arm the number of furrow-spines is reduced to a single distal and a single proximal spine. At the base of the arm a lateral spine occurs opposite every third adambulacral; further out one is opposite every alternate adambulacral. The lateral and subambulacral spines are thickly spattered with minute crossed pedicellariae, looking like sand-grains adhering to the spines. The oral plates carry 1 actinostomial spine, a large, laterally directed proximal furrow-spine, a smaller distal furrow-spine, one long, slender, fluted suboral spine near the midline, and one short suboral spine near the distal furrow-spine.
Material Examined: Arms and discs of about five individuals, all taken by Dr. R. K. Dell at Dom. Mus. Station B.S.209, in 270 fathoms off Mayor Island, Bay of Plenty.
Holotype: An arm which, with a paratype disc, and also the rest of the material, is in the Dominion Museum Wellington.
Remarks: Brisingenes delli is distinguished from Brisingenes mimica Fisher by having only 14 (as against 16) arms, and only 15–17 (as against 25–30) costae The adambulacral armature is also distinctive. From Brisingenes anchista it is distinguished by the number of costae (40 in anchista), and by the adambulacral armature, the number of arms being the same in both species. Fisher (1919) points out that Brisinga bengalensis Alcock and Wood-Mason and Brisinga gunnii Alcock are 14-rayed forms whose exact systematic position is uncertain; they must therefore be considered as potential species of Brisingenes. Both of these forms have an entirely different adambulacral armature (see Fisher, 1919, p. 534) from the New Zealand material, and more numerous costae.