194 DISCOVERY REPORTS 



Subgenus Pteraster 



Pteraster lebruni Perrier 



Pteraster lebnttii Perrier, 1891, p. 144, pi. 13, figs. ^a-^b. — Ludwig, 1903, p. 29, pi. 3, figs. 25-28. — 

 Clark, 1908, p. 286 (key). — Fisher, 191 1, p. 369 (key). — Koehler, 1917, pp. 49-52. — 1920, p. 170. 



St. 148. OflF Cape Saunders, South Georgia, 132-148 m., grey mud, stones, i specimen. 



St. 1958. 61° 17-9' S, 52° 50-8' W, 740 m., I specimen. 



St. WS 81. 8 miles north-west of North Island, West Falkland Islands, 81-82 m., sand, 5 speci- 

 mens. 



St. WS 84. 7I miles south-west of Sea Lion Island, East Falkland Island, 75-74 m., coarse sand, 

 shells, stones, i specimen. 



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



St. WS 93. West Falkland Island, 51° 51' S, 61° 30' W, 133-130 m., grey sand, 3 specimens. 



St. WS 97. North of Falkland Islands, 49° 00' 30" S, 61° 58' W, 146-145 m., i specimen. 



St. WS 210. Falkland Islands, 50^^ 17' S, 60^ 06' W, 161 m., green sand, 1 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 782A. North of Falkland Islands, 50° 29J' S, 58° 23!' W, 141-146 m., i specimen. 



St. WS 831. 50" 50' 30" S, 66° 10' 30" W, 98-102 m., 3 specimens. 



St. WS 871. 53° 16' S, 64° 12' W, 336-341 m., 7 specimens. 



The largest specimen has R 72 mm., r 30-32 mm., R = 2-25 r, br 35-36 mm. (St. 

 WS 782). 



This species so closely resembles Pt. militaris in general habit that the figures of the 

 latter species published by me in 191 1 would serve almost equally well for lebrimt. The 

 observation applies especially to the actinal surface. The width of the actinolateral 

 membrane and the manner in which the adambulacral web extends beyond the outer 

 spine of its comb across the actinolateral membrane is characteristic of both species. 



The appearance of the supradorsal membrane is variable, as in all species of Pteraster, 

 due, in part, to accidents of preservation, crowding in containers, etc. In some specimens 

 it appears thick and folded, with no spinelets visible, as in my figure of Pt. militaris 

 (Fisher, 191 1, pi. 98, fig. i). In the largest specimen, and a number of others (e.g. 

 St. WS 81), the supradorsal membrane is not well hardened so that the ends of numerous 

 spines protrude, very much as in my figure of Pt. marsippus and Pt.jordani (Fisher, 191 1 , 

 pi. 100). The supradorsal membrane is crowded with deposits which have been figured 

 by Ludwig. The abactinal paxillae have a low pedicel and usually three much longer 

 spinelets, of which one is commonly stouter than the other two. 



The adambulacral combs of large specimens have as many as 7 or 8 spines, and the 

 mouth-plates 6-8 marginal spines, of which the two or three innermost are much longer 

 than the others. The series of each plate is independently webbed. The first adam- 

 bulacral webs of a mouth angle are not continuous across the interradius. 



The suboral spines are variable in size and shape, but are always much thicker than 

 the innermost marginal spine. Although usually subcircular in section almost to the 

 tip, the terminal fourth or fifth may be triangular in section. In some specimens (e.g. 

 Sts. WS 81, WS 871), however, this triagonal condition extends throughout the distal 



