AND THE FISH THEREOF. 31 



the "Fountain-fish" of the early voyagers to Spitsbergen ; Salpa maxima 

 often appears, of which sometimes a hundred or more individuals are united 

 together, forming long chains, known as " Serpents de mer" several of which 

 often swim in company, producing the most intense phosphorescence ; from 

 these chains each individual detaches itself, in its turn, for purposes of 

 reproducing its species. The progeny is a single individual which, totally 

 dissimilar from its parent, carries on its solitary existence until it, in its turn, 

 produces a whole chain, consisting of hundreds linked together, but each like 

 the grandmother. 



Tethys fimbria is less frequent ; it is one of the most beautiful, as it is the 

 largest, naked sea-snail in the Mediterranean ; it is furnished with lateral 

 protuberances, extending on either side of the back, which it moves back- 

 wards and forwards to serve as oars, besides a sail which, in a specimen 

 5 inches in length, measured as much as 4^ inches across, the foremost 

 lateral extensions measuring 2 inches ; it is particularly remarkable for the 

 phosphorescence it produces. 1 



The Nautilus, or Paper sailor [Argonauta papiraced), is not uncommon in 

 the waters of the islands of Lissa and Lesina, and occasionally, but quite 

 accidentally, it finds its way as far north as the Gulf of Trieste. 



Some minute species of Pteropods, probably belonging to the genus of 



are Ciliograda, creatures which are, for the most part, more or less spherical in shape, or else 

 simulate strips of riband, transparent as the purest crystal, and moving through the water by 

 means of variously-arranged bands of thread-like hyaline fins, which, as they flap, all keeping 

 exact time, in each long row, decompose the rays of light, and glitter with the hues of the 

 rainbow. More exquisitely beautiful creatures than these Beroidce (for so the tribe is called) do 

 not exist among all the wondrous beings that people the seas. The elegance of their shape is 

 equalled by the grace of their movements ; and when the prismatic lustre of their bands of cilia 

 marks the course of their crystal bodies, as they swim with gentle motion through the water, they 

 seem as if they were diamonds endowed with life. Some, such as the Beroe cucumis, one of the 

 most characteristic of the northern forms, yet having a wide range to the south, although in fewer 

 numbers, are tinged with a charming amethystine blush. This is the " Fountain-fish " of the early 

 voyagers to Spitzbergen, who, mistaking the cause of the eight bands of iridescence, gleaming 

 along the sides of its body, fancied they were so many rivulets of lustrous water. — Forbes and 

 Godwin-Austen, "Natural History of the European Seas." 



1 See Dr. Grube's work, " Ein Ausflug," l\:c., p. 29, and illustration 12. Taf. i. 



