BRITTLE-STARS AND SAND-STARS. 119 



its rays ; and it is a curious circumstance, in connection with the 

 entire fraternity of Echinoderms, that this same number, five, 

 seems, in almost everything, to reign predominant in the details 

 of their organization. It is not unusual, however, to meet with 

 Star-fish having only four or even three rays ; and not long since 

 there was a specimen of Uraster rubens in one of the tanks in the 

 Regent's Park Gardens which had but two rays, and those on 

 exactly opposite sides of the central disc, so as to give the animal 

 a spindle-form. The truth is, the Star-fish and their allies are 

 endowed with the most extraordinary powers of voluntary dis- 

 memberment ; and when they have the misfortune to injure 

 any of their members they very deliberately fling them away, 

 or rather crawl off and leave them behind. But it is only for a 

 time that the Star-fish goes with less than its full complement of 

 members, as new rays speedily sprout out, and, in due time, the 

 animal regains its normal condition. 



In so far as is known, the habits of all the true Star-fish are 

 pretty much alike, though in form and appearance there is a 

 considerable difference between the various species. One of the 

 most elegant of those found around our own shores is the 

 well-known Sun-star (Solaster papposa), a magnificent fellow, 

 with from twelve to fifteen rays, and which, decked as it is 

 in rich tints of scarlet and purple, has a truly gorgeous appear- 

 ance as it clings to the rocks with the waves curling and playing 

 around it. 



Brittle-stars and Sand-stars are Star-fish with a difference. 

 These animals are distinguished by the greater length and 

 slenderness of the rays, which, possessing neither groove nor 

 suckers, differ essentially from the corresponding parts of the 

 true Star-fish. When the Fish House in the Zoological Gardens 

 was first opened, several of these odd-looking little creatures were 

 exhibited in one of the tanks, and the singularity of their ap- 

 pearance attracted much attention. It was speedily discovered, 

 however, that they were not of a kind to be successfully treated 

 in the Aquarium, and no new supply has been obtained to take 

 their place. The Brittle-stars are extremely abundant around 

 most parts of our coast, most of the species inhabiting deep water, 

 where they appear to spend an active existence, swimming and 

 crawling about with considerable facility, by means of their elon- 

 gated spiny rays their only organs 01 locomotion. The common 



