PROTOZOA, CCELENTEEA, AXD ECHINODEBMA 105 



ones ; and indeed it may be said that the recent work 

 on deep-sea Asteroids does not throw much new light 

 either 011 the phylogeny of the group or on their 

 palaeontological history. 



The genus Brisinga,, at one time supposed to be 

 a connecting link between the star-fishes and the 

 brittle stars (Ophiurids), has recently been shown to 

 be closely related to the families Heliasteridea, Ech- 

 inasteridea, and others typical of the class Asteroidea ; 

 and, as Sladen has pointed out, the peculiarities of 

 structure that it exhibits are probably due to its ex- 

 treme isolation and the influence of its abysmal habitats. 



But no work on the deep-sea fauna would be 

 complete without some reference to Brisinga. Dis- 

 covered by Asbjornsen in 1853, in 200 fathoms of 

 water in the Hardanger fjord, and described in a 

 splendid memoir by the elder Sars, it excited great 

 interest among naturalists. The great brilliancy of 

 the phosphorescent light that it gave out on being 

 brought on deck, the remarkable tendency that it had 

 to cast off some of its numerous long, thin, ophiurid- 

 like arms, and some of the general features of its 

 internal anatomy were points that were considered at 

 the time to be sufficient to justify the establishment 

 of a separate sub-order for the family Brisingidse. 



