178 DISCOVERY REPORTS 



Genus Solaster Forbes 

 Solaster Forbes, Mem. Wernerian Nat. Hist. Soc, viii, 1839, p. 120. Type Asterias endeca Linnaeus. 



Solaster regularis Sladen 



Solaster regularis Sladen, 1889, pi. 60, fig. i; pi. 62, figs. 5, 6. — Fisher, 191 1, p. 323. 

 Crossaster australis Perrier, 1891, p. 113, pi. 10, figs, la-id. 

 Solaster australis Ludwig, 1905, p. 63. — Fisher, 191 1, p. 323. 



St. WS 80. Falkland Islands, 50° 57' S, 63° 37' 30" W, 152-156 m., fine dark sand, 2 specimens. 



St. WS 97. Falkland Islands, 49 "^ S, 61° 58' W, 146-145 m., i specimen. 



St. WS 108. Falkland Islands, 48° 30' 45" S, 63° 33' 45" W, 1 18-120 m., fine dark sand, i 

 specimen. 



St. WS 243. North-east of Falkland Islands, 51° 06' S, 64° 30' W, 144-141 m., coarse dark sand, 

 2 specimens. 



St. WS 773. East of Cape Tres Puntas, 47° 28' S, 60° 51' W, 291 m., i specimen. 



St. WS 804. Falkland Plateau, 50° 22f' S, 62° 49' W, 150-143 m., i specimen. 



St. 824. South-east of East Island, Falkland Islands, 52° 29J' S, 58'' 27^' W, 146-137 m., i 

 specimen. 



Eight specimens have 9 rays and one has 10 rays (St. WS 243). The type has 8 rays, 

 Ludvvig's specimen 10, Perrier's, 9 or 10. 



This species is as variable as the north Pacific Solaster paxillatus Sladen and S. 

 borealis Fisher. As in these species, there is a form with small paxillae, one with large, 

 and intermediates. Sladen's figure represents an aberrant extreme, just as his figure does 

 in the case oi paxillatus, in which, also, the rays vary from 8 to 10. 



There are scarcely 2 specimens of regularis from different localities which are alike. 

 The example from St. WS 824 (R 84 mm., r 25 mm., br 17 mm.) has relatively large, 

 close-set paxillae with numerous (e.g. 18) slender, sometimes terminally expanded, 

 thorny spinelets which appear stout, blunt and papilliform on account of the soft pulpy 

 investment. The proximal furrow combs have usually 5, long, slender, basally webbed 

 spines, also appearing blunt and stout on account of the sheath. These diminish to 3 on 

 outer part of ray. Proximally the transverse, curved, subambulacral comb usually has 

 6 slightly longer, heavily sheathed spines; distally there are 5. In a specimen from St. 

 WS 80 there are 7 with a smaller eighth at outer end of series. These spines are stout, 

 subterete, tapered, but usually appear coarser and blunter than they really are on 

 account of the sheath. Each mouth-plate carries about 9 marginal spines, the inner 

 enlarged and terminally bifid, while parallel to median suture there are 7 or 8 suboral 

 spines, the inner of which is subequal to the 2 "teeth ". Inferomarginals of conspicuous 

 size, broader than long, much like those of S. paxillatus (Fisher, 191 1, pi. 88). The first 

 10 correspond to the first 17 or 18 adambulacrals. 



There is a specimen from St. WS 243 (R 100 mm., r 36 mm., br 26 mm.) referable to 

 the same forma but, owing to inflation of disk and rays, the paxillae are not so closely 

 placed. The sheath of all the spines is unusually thick and pulpy. 



Forms with small paxillae are represented by figures of Sladen's type and those of 

 Crossaster australis Perrier. In the latter the dorsal integument is unduly shrunken by 



