provided by NMNH Antarctic Invertebrates

“Anteliaster australis sp.nov.

(Fig. 1, 1-1d; Plate IX, figs. 2, 3)

DIAGNOSIS. Differing from C. coscinactis Fisher in lacking unguiculate straight pedi­cellariae and in having a relatively close-knit skeleton with usually only 1 papula to each area of disk and rays; spinelets short, close-set, interspersed with numerous crossed pedicellariae, attached to the plates, giving the body a uniform finely granulose appear­ance; to the touch the texture is like that of fine sand-paper. R 35 mm., r 5 mm., br 6 mm., R= 7r.

DESCRIPTION. The body is covered with slender, short, thorny tipped spinelets, rather uniformly spaced about their own length; 1-3 spinelets to a plate. Everywhere between the spinelets are crossed pedicellariae, attached to surface of plates and also to membrane of papular areas. The spinelets, only slightly longer than the pedicellariae, combine with them to give the surface a rather uniform granular appearance.

Marginal plates lateral in position. Superomarginals with 3 spinelets, reduced to 2 and 1 at end of ray. Inferomarginals with 2 spinelets, reduced to 1 distally, before the reduction of superomarginal spinelets occurs. Actinals with 1 spinelet.

The skeleton is basically like that of A. coscinactis (Fisher, 1928, pl. 29, fig. 1) but the skeletal intervals relative to size of plates are much smaller; that is, the mesh is less open. If the specimen were larger (R 63 mm. in coscinactis) it is possible the difference would be less. The secondary ossicles uniting inferomarginals to actinals of coscinactis are lacking in australis, while the secondary intermarginal ossicles extend only a fourth the length of ray (in larger specimens, undoubtedly farther). The dorsolateral skeleton is irregular as in coscinactis, the plates 3- and 4-lobed, and the smaller papular areas are in about 3 irregular longiseries. There is one series of actinals extending far along ray and a short second series about one-third length of ray. The papular areas are distributed as in the figure of coscinactis but contain a single papula, except for a few intermarginal areas proximally which have 2.

In a smaller specimen (St. WS 86) most of the proximal dorsolaterals are 3-lobed and imbricate more regularly.

Adambulacral spines conspicuously longer than marginals and actinals, disposed in transverse series, 4 on first 3 or 4 plates, then 3. The outermost spine is clavate, the furrow spine terete and much more slender, while the middle one is intermediate. Each mouth-plate has 2 short spinelets on the inner border, extending over the peristome; and in line with the inner spinelet is a series of 3 successively longer ones on the surface of the narrow plates. On the distal furrow corner of plate is a spinelet conspicuously shorter and slenderer than outermost suboral. The first pair of adambulacrals behind mouth-plates is separated by a slight interval. The disposition of oral spines is closely similar to that of A. coscinactis (Fisher, 1928, pl. 29, fig. 1b).

Madreporic body small, with few coarse striae, situated near margin at top of inter-brachial sulcus.

There are no straight pedicellariae. The crossed closely resemble those of A. cosci­nactis, differing only in minor details. They vary in length from 0.18 to 0.4 mm., the greater number being 0.27-0.35 mm. in length. The largest are found on the actinal and inferomarginal plates where they are mixed with average sized; while the smallest are on the abactinal surface, there mixed with medium sized which are slightly smaller than the actinal average.

The gonads open in the interval between the inferomarginal and actinal plates, 3 or 4 mm. from the interbrachial angle. Each gonad consists of a cluster of relatively large branched tufts, the lobules being irregular in form and unequal in length. The inter-brachial septum is very rudimentary, practically non-existent, the coelom of disk being therefore undivided. This is an advantage to the animal which ingests its food entire. In the stomach of a specimen with disk diameter of 9 mm. were two gastropod shells, the larger a sharp cone 9 mm. long.

TYPE LOCALITY. St. WS 248, East Falkland Island, 52° 40' S, 58° 30' W, 210-242 m., fine green sand, pebbles, shells, 3 specimens.

SPECIMENS EXAMINED. Including the above, 11 specimens.

St. 156. South Georgia, south-east of Larsen Point, 260 m., mud, 1 specimen.

St. 160. Near Shag Rocks, 177 m., grey mud, stones and rock, 2 specimens.

St. WS 81. North-west of North Island, West Falkland Island, 81-82 m., 1 specimen.

St. WS 85. Falkland Islands, 52° 09' S, 58° 14' W, 79 m., sand and shell, 2 specimens.

St. WS 825. North-east of East Island, Falkland Islands, 135-144 m., 1 specimen. St. WS 871. Falkland Islands, 53° 16' S, 64° 12' W, 336-341 m., 1 specimen.

REMARKS. At Sts. 156 and 160 Pedicellaster hypernotius was taken. There is consider­able superficial resemblance between the two species.

If the identification of the specimens listed as Anteliaster scaber (Smith) is correct, australis is a very different species. The spinelets of scaber are longer and the crossed pedicellariae have a different form.”

(Fisher 1940: 215-217)