ASTEROIDEA 215 



R = 25 mm., r = 5 mm. The type of P. antorcticus, from Bellingshausen Sea, 450 m., 

 measures R 30 mm., r 5 mm. 



The principal difference between antarcticus and hypernotius, according to Ludwig, is 

 the presence of 3 spinelets on each carinal plate of the former and only one in the latter 

 species. In the Discovery specimens the number varies from i to 3, and occasionally 

 to 4. 



The larger of the two varieties of crossed pedicellariae is abundant on the sides of ray 

 and distally they encroach upon the abactinal surface. They are very similar to those of 

 P. magister Fisher^ a relatively gigantic species from Bering Sea and the Alaskan coast, 

 but are unlike the major crossed pedicellariae of P. typicus (Fisher, 1928, pi. 26, fig. i). 

 The jaw varies between 0-3 and 0-4 mm. in length. The minor pedicellariae are circa 

 0-22 mm. long. There are also pedicellariae intermediate in size and form between the 

 major and minor varieties. Very small, blunt, triangular straight pedicellariae (0-15 mm. 

 long) occur along the furrow margin, as figured by Sladen (1889, pi. 105, fig. 7). In the 

 specimen from St. 1955, in which R is only 9 mm., the two sorts of crossed pedicellariae 

 are well differentiated. 



In these small specimens there is only i series of actinal plates. The extraordinary 

 development of the actinal system of P. magister is not even suggested. 



The only other Antarctic Pedicellaster is formatus Koehler (1920, p. 106, pi. 16, 

 figs. I, 9, 10; pi. 17, figs. 6, 7; pi. 58, fig. 4) from 120 fathoms, 66° 08' S, 94° 17' E. It 

 differs chiefly in having stouter plates and may ultimately prove to be a form of hyper- 

 notius. 



The Discovery specimens extend the known range of the species from Bellingshausen 

 Sea along the Antarctic Archipelago to South Georgia and Shag Rocks. 



Genus Anteliaster Fisher 



Anteliaster Fisher, 1923, p. 252; 1928, p. 69. Type A. coscinactis Fisher. 



Anteliaster australis sp.nov. 

 (Fig. I, i-iJ;PlateIX, figs. 2, 3) 



Diagnosis. Differing from C. coscinactis Fisher in lacking unguiculate straight pedi- 

 cellariae and in having a relatively close-knit skeleton with usually only i 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 appear- 

 ance; 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. 



1 Fisher, 1928, p. 63, pi. 26, fig. 2; pi. 27, fig. 2. 



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