ASTEROIDEA 171 



Sladen's specimen from 1325 fathoms off the Chonos Archipelago merits further 

 examination on account of the great depth. One suspects the existence of a deep water 

 form analogous to L. fiirciUiger, Alaska to Galapagos Islands, 192-1100 fathoms. 



Ludwig's figures (1903, pi. 3, fig. 23) do not represent typical abactinal spinelets of 

 stellam, ]udgmg by specimens from the Falkland Plateau illustrated herewith, although 

 they are similar to Koehler's photographs of the type of L. pentactis (1920, pi. 68, fig. 3). 



Type locality. Not given. Taken by the ' Challenger ' at three localities, off the 

 coast of Chile, between 45° 31' S and 50° 56' S, 40-1325 fathoms. 



Distribution. Falkland Plateau to 48° S ; Strait of Magellan ; coast of Chile to 

 45° 31' S, 80-267 m. (except Sladen's record of 1325 fathoms which is open to question). 

 (Western Antarctica, e.g. 71° i4'-7i° 19' S, 87°-89° W, 450 m., Ludwig; possibly a 

 different race.) 



Lophaster marionis sp.nov. 



(Fig. F, i-id; Plate XIII, fig. i) 



Diagnosis. Similar in general form to L.fiircilliger Fisher, having narrow rays, small 

 disk, and long pedicelled, penicillate paxillae, the inferomarginal being especially 

 prominent ; differs in lacking a definite series of actinal plates on ray and in details of 

 spinulation especially in the more numerous unequal spinelets of marginal paxillae. 

 R 30 mm., r g mm., br 10 mm. including marginal paxillae. 



Description. Paxillae not crowded but distinctly spaced, penicillate, with 15-20 

 delicate, divaricate, usually 3-pronged, glassy spinelets about o-8 mm. long on disk; 

 pedicel slender, about as long as spinelets. Paxillae rapidly diminishing in size on outer 

 half of ray where the pedicels are shorter than the 3-6 or 7 spinelets. The cruciform 

 delicate abactinal plates (base of paxillae) are arranged in chevrons pointed toward 

 centre of disk ; the first chevron has 1 1 plates from side to side of ray, not counting the 

 much larger superomarginals. The number then drops to 9, 7, and on outer third of ray 

 to 5, although some irregularity exists. The plates are also aligned parallel to the 

 superomarginals, but lateral-most row contains more plates than superomarginal series. 

 Papulae few, 3-5 or 6 per area on disk ; 2 or 3 on proximal part of ray ; i or o on outer 

 third. Madreporite small, 0-9 mm. in diameter, situated at mid-r. 



Marginal plates one above the other, 20 to a ray in each series. Superomarginal 

 paxillae abruptly larger than dorsolaterals; spinelets on proximal paxillae 12-15, 

 similar to abactinal but a little stouter and varying in length from 075 to 0-85 mm. ; 

 proximal pedicels longer than spinelets. 



Inferomarginal paxillae with terminally compressed pedicels slightly longer and 

 decidedly stouter than superomarginal ; spinelets proximally about 20, those on dorsal 

 side of tip o-6 mm. long, increasing to i-i mm. on ventral. The shorter have 3 or 4 

 prominent prongs but are broader distally than the abactinal spinelets. The longer 

 spinelets have 4-7 prongs (Fig. F, i b). The first i or 2 inferomarginals are smaller than 

 the succeeding. On distal third of ray the pedicels rather rapidly shorten and are about 

 half as long as the proximal. 



