ASTEROIDEA 173 



subambulacrals is 4, 3, 2 ; in stellans it is 6 or 5, and 4 only sporadically, or at tip of ray. 

 The abactinal paxillar spinelets of stellans (o-y-o-g mm. long) have 5 or 6 sharp prongs 

 (Fig. E, 3^) rather than the 3 or 4 of marionis. Ludwig's figures (1903, pi. 3, fig. 23) do 

 not represent typical abactinal spinelets of the stellans of Falkland region but are similar 

 to Koehler's figures of the spinelets oi L. pentactis Perrier (Koehler, 1920, pi. 68, fig. 3). 

 Spines of L. qiiadrispinus have not been figured. 



Out of this emerges the probability that stellans and qiiadrispinus are representative 

 small species of the eastern and western hemispheres, connected by a pan-Antarctic 

 species (or series of small species) of which marionis is a northern representative. 



Lophaster gaini Koehler 



Lophaster gaini Koehler, 1912, p. 42, pi. 4, figs. 4, 5, 12, 13. — 1920, p. 143, pi. 31, figs. 8, 9; pi. 66, 

 fig. 8. 



St. 187. Neumayr Channel, Palmer Archipelago, 64° 48' 30" S, 63° 31' 30" W, 259 m., mud, i 

 specimen. 



St. 599. West coast of Adelaide Island, 67° 08' S, 69° o6i' W, 203 m., i specimen. 



Koehler has fully described and figured this species, which appears to have no very 

 close relatives. One might quite naturally assume it to be an Antarctic equivalent of 

 L. stellans of the Cape Horn-Falkland region but this seems to be definitely not the case. 

 L. gaini has highly characteristic abactinal spinelets which are needle-like and end in a 

 single hyaline point, while in stellans these spinelets are characteristically 3- or 4-pronged 

 as illustrated by Ludwig (1903) and Koehler (1920, pi. 68, fig. 3). I have verified the 

 spine characters of both species. In L. gaini the marginal, especially the inferomarginal, 

 spines are unusually coarse, rather few in number, and acicular in form (see Koehler, 

 1920, pi. 31, fig. 8). About 5 of the spines are conspicuously larger than the others and 

 on the outer part of the ray they form a transverse comb, flanked on the adoral side by a 

 group or series of 5 or 6 shorter spines. On the outer third of the ray the marginal plates 

 and spines resemble those of Ganeria. 



Type locality. South Shetland Islands (King George Island) 420 m., mud and 

 stones. 



Distribution. South Shetland Islands, Palmer Archipelago, and Adelaide Island, 

 203-420 m. Adelie Land, 318-400 fathoms; Queen Mary Land, no fathoms. Probably 

 a continuous circumpolar distribution. 



Lophaster densus sp.nov. 

 (Fig. E, 4-4C; Plate XIII, figs. 2, 3) 

 Diagnosis. Rays 5; Ri9mm., r 7-5 mm., br 8 mm. Disk rather high and rays 

 strongly convex, the marginals being on the actinolateral border; paxillae close-set, low, 

 compact, the abactinal view suggesting a short-rayed Leptycliaster; marginal paxillae 

 close-set, low, not projecting as in typical Lophaster, the very even surface of the abactinal 

 spinulation passing without a break into that of inferomarginal paxillae; actinal surface 

 with well-developed actinal interradial areas and suggesting a five-rayed Solaster. 



D .\X ^4 



