LUMINOUS ECHINODERMS. 31 



from the centre of the disk ; flashing out now upon one arm, 

 again upon another, or suddenly illumining the entire star in 

 a brilliant aureola of phosphorescence. 



This resplendent creature is especially common, according 

 to Sir Wyville Thompson, off the coast of Stornaway and 

 Shetland ; and the nets, when hauled in, were often over- 

 laden with masses of these gorgeous forms, which emitted a 

 light of brilliant uranium green. Curiously enough, the 

 young star-fishes exceeded the adults in the richness of their 

 display. The gleams were not constant, but extremely erratic, 

 appearing and re-appearing in a bewildering manner ; and, 

 according to the same naturalist, the most striking exhibitions 

 were seen in very young ones. 



The star-fishes known as Ophiuroids are among the most 

 abundant of deap-sea forms. On the " Challenger," about 

 several hundred species were brought up in the trawl from a 

 depth of from half a mile to two and a half miles. In our 

 own waters, two kinds w have been observed to emit a light 

 of singular brilliancy. 



Even more beautiful than these, as regards their luminosity, 

 are the Brisingas, 28 one of which is shown with its light in 

 Plate VIII., Fig. 1. This animal has nineteen long, snake- 

 like arms, branching from a small central circular body. Its 

 color in the daylight is a rich orange red ; but at night, when 

 taken from the dredge, it displays a vivid phosphorescence. 



This attractive animal was first observed near Bergen, 

 Norway, by Charles Abjordsen, who took a specimen in two 

 hundred fathoms of water. Regarding it, he said, " it is a 

 true gloria maris" and gave it the name of Brisinga, one of 

 the jewels of the Goddess Freya. 



The Brisingas have the faculty, common to many of their 



