REPORT ON THE ASTEROIDEA. 189 
2. Leptoptychaster arcticus, Sars, sp. 
Astropecten arcticus, Sars, 1851, Reise i Lofoten og Finmarken, Nyt Mag. f. Naturvidensk., Bd. vi. 
p- 161; Fauna Litt. Norvegie, 1856, Heft 2, p. 61, pl. ix. figs. 16-18; Oversigt af Norges Echino- 
dermer, 1861, p. 32. 
Astropecten Liitkeni, Barrett, 1857, Ann. and Mag. Nat. Hist., ser. 2, vol. xx. p. 46, pl. iv. fig. 3, a, 0, ¢. 
Archaster arcticus, Perrier, 1878, Nouv. Archives Mus. Hist. Nat., 2e Sér., t. i, pp. 32, 88. (Also 
Verrill, and Storm). 
Localities. —“ Porcupine ” Expedition : 
Station 65 (1869). Between the Shetland and the Faerée Islands. Lat. 61° 10’ N., 
long. 2° 21’ W. Depth 345 fathoms. Bottom temperature —1°1 C.; surface tempera- 
ture, 11°°1 C. 
Station 82 (1869). In the Faerée Channel. Lat. 60° 0’ N., long. 5° 18’ W. Depth 
312 fathoms. Bottom temperature 5°-2 C.; surface temperature 11°:2 C. 
Station 3 (1870). West of Ushant. Lat. 48° 31’ N., long. 10° 3’ W. Depth 690 
fathoms. 
Remarks.—This form was originally described as an Astropecten. Some subsequent 
writers have retained it in that genus, whilst others have regarded it as an Archaster. I 
am unable to agree with either of these determinations. After careful study I consider that 
its structure accords in all points of generic import with the genus Leptoptychaster estab- 
lished by Mr Smith for the foregoing form from the Southern Ocean, and I have therefore 
referred the species under notice to that genus. It is readily characterised by the aborted 
supero-marginal plates, the short but broad infero-marginals (both alike unarmed), the 
well-developed actinal interradial areas, the character of the paxille, and likewise that 
of the armature of the adambulacral plates. Finally, the species has more or less well- 
developed superambulacral plates ; the whole forming a combination of characters which 
accords neither with Archaster nor Astropecten. 
2a. Leptoptychaster wrcticus, var. elongata, nov. 
The American examples of this species, of which a large series was taken at Station 49, 
are all distinctly longer in the ray, and have the paxill of the abactinal area some- 
what more delicate and less compact in character than in the European forms, although 
even in these some variation occurs. It would, however, be an easy matter to say which 
were the American examples out of a large number of mixed specimens, and on these 
grounds I consider that we are dealing with a well-marked variety. 
Localities.—Station 46. Off the coast of North America, east of New Jersey and 
Long Island. May 6, 1873. Lat. 40° 17’ 0” N., long. 66° 48’ 0” W. Depth 1350 
fathoms. Blue mud. Bottom temperature 37°:2 Fahr.; surface temperature 40°:0 Fahr. 
1 Recorded by Sir Wyville Thomson in The Depths of the Sea; but I have not seen a specimen from this 
locality. 
