Species of British Echinodermata. 125 



to regard as distinct species. The variety from the deepest water 

 of the Shetland Islands is peculiarly marked. It rarely exeeds 

 2 inches in its greatest diameter, is of a brilliant saffron-yellow 

 colour, and has the rays peculiarly rounded and firmer in struc- 

 ture than usual. The spines, also, are much shorter and more 

 delicate than in ordinary specimens, and have their apices much 

 more distinctly trifid. 



The largest specimens which we have seen of this species are in 

 Mr. Bean's collection, and were procured by him at Scarborough. 

 A monstrosity in our collection has six, and another seven rays. 



Cribrella sanguinolenta is an Arctic species of very extensive 

 range. It has been met with in the seas of Norway, Sweden, 

 the Faro Islands, Finmark, Iceland, Greenland, western North 

 America, and Kamtschatka. 



Fam. III. Asteriadae. 

 A special anal opening. Four rows of ambulacral tentacula. 



Genus XIX. Stichaster, Miiller & Troschel. 



[Stichaster, Miiller & Troschel, 1840. Asteracanthion, Miiller & Troschel, 

 1842 (partly).] 



Body convex, with five greatly elongated, slender, compact, 

 well-rounded rays, closely covered above by short tubercular 

 spines, and pierced with very numerous tentacular pores ar- 

 ranged in longitudinal rows. No marginal plates or spines. 

 Suckers quadriserial. Anus central. Pedicellariee numerous, of 

 one kind only. Madreporiform tubercle close to the margin of 

 the disk, not covered with spines. 



The presence of four, instead of two, rows of ambulacral ten- 

 tacula give the Asterias rosea of Miiller claims to be placed, not 

 only in a different genus, but in a different family from the 

 Asterias sanguinolenta of the same author, with which it was 

 associated by Professor Forbes in the genus Cribrella. The 

 species has closer affinities with Asterias restricted {Asteracan- 

 thion, M. & T.), in which genus it was arranged by Miiller and 

 Troschel in their ' System der Asteriden.' The peculiarly pro- 

 duced, well-rounded, compact arms of this species, with the 

 close covering of tubercular spines, and the lateral position of 

 the Madreporiform tubercle, justify its separation from the 

 typical species of Asterias. 



Stichaster roseus (0. F. Miiller). 



1776. Asterias rosea, Miiller, Zool. Dan. Prod. p. 234. no. 2837. 



1841. Cribella rosea, Forbes, British Starfishes, p. 106. 



1842. Asteracanthion roseus, Mull. & Troschel, Syst. der Asteriden, p. 17.' 

 1861. Stichaster roseus, Sars, Oversigt af Norges Echinodermer, p. 86. 



A deep-water species, an inhabitant of the Scandinavian seas. 



