588 THE VOYAGE OF H.M.S. CHALLENGER. 



The adambulacral plates are small, and their armature consists of two short, equal, 

 slightly flattened, slightly tapering and obtusely tipped spinelets, closely placed. I have 

 not detected the presence of any forficiform pedicellarias on the actinal surface of this 

 species. 



The adambulacral furrows are narrow, and almost arched over by the armature of the 

 adambulacral plates when contracted. The tube-feet are crowded, and disposed in quadri- 

 serial arrangement. 



The madreporiform body, which is small, and almost obscured by a surrounding 

 vesiculated membrane, is placed very near the margin. 



Colour in alcohol, a bleached yellowish or warm light brownish white. 



Locality. — Off Nightingale Island, Tristan da Cunha group. Depth 100 to 150 

 fathoms. 



Remarks. — This species resembles Asterias (Stolasterias) tenuispina in general char- 

 acter and appearance, but differs in such essential details that I can entertain no doubt 

 as to its specific distinction, although I feel great reluctance in establishing a new species 

 in such a difficult genus on the single example which is unfortunately all that was 

 procured. Asterias (Stolasterias) eustyla is distinguished from the other members of 

 the Asterias tenuispina group (the subgenus Stolasterias) by its five rays, by the oblique 

 series of three spines on the infero-marginal plates, by the presence of two spines in 

 the armature of the adambulacral plates, and by the interrupted but definite intermediate 

 series of spinelets between the median abactinal and supero-marginal series. 



Asterias mollis of Hutton is probably nearly allied, but differs in the disposition of the 

 intermediate abactinal spines, in the size and propinquity of the spinelets generally, in the 

 character of the wreaths of pedicellarise at their bases, and in the different form of the rays. 



23. Asterias (Stolasterias) glacialis, 0. F. Muller. 



Asterias glacialis, O. F. Muller, 1776, Zool. Dan. Prodr., p. 234. 



Asterias spinosa, Pennant, 1777, British Zoology, vol. iv. p. 62. 



Asterias angulosa, 0. F. Muller, 1788, Zool. Dan., vol. ii. p. 1, tab. xli. 



Asterias eehinophora, Delle Chiaje, 1825, Memoiie sulla stor. e not. Anim. s.'vert.' Napoli, vol. ii. 



p. 356, tav. xviii. fig. 5. 

 Stellonia glacialis, Nardo, 1834, De Asteriis, Ok en's Isis, p. 716. ' 

 Stellonia angulosa, Agassiz, 1835, M6m. Soc. Sci. Nat. Neuchatel,jt. i. p. 192. 

 Stellonia webbiana, d'Orbigny, 1839, in Webb and Berthelot, Hist. Natalies Canaries, t. ii., 2e partie, 



Zoologie, p. 148, Echin., pi. ii. figs. 8-13. 

 Uraster glacialis, Forbes, 1841, Hist. Brit. Starfishes, p. 78. 

 Asteracauthion glacialis, Muller and Troschel, 1842, System der Asteriden, p. 14. 

 Asteracanthion webbianum, Dujardin and Hupe, 1862, Hist. Nat. Zooph. Echin. (Suites h Buffon), 



p. 340. 

 Asterias madeirensis, Stimpson, 1862, Proc. Boston Soc. Nat. Hist., vol. viii. p. 263. 

 Marthasterias foliacea, Jullien, 1878, Bull. Soc. Zool. France, p. 141. 



Locality. — Off St. Vincent, Cape Verde Islands. Depth and conditions not stated. 



