98 POPULAR HISTORY OF THE AQUARIUM. 



ing tentacLila, wliicli have the appearance of a number of 

 delicate worms^ clustering and twisting about each other. 

 It is very remarkable^ even among the changing sea-flowers, 

 for the extent of its changes in form. Now it is an almost 

 flat button fixed to a piece of rock ; now it is an upright 

 cylinder, with a many-threaded head ; and now it is a nar- 

 row worm three or four inches in length. It has been ob- 

 served that its greatest tendency to elongation is in the 

 dark. Its body is of a light buff colour, marked with irre- 

 gular lines of brown, or interrupted light bands running 

 down lengthwise. The disc, when expanded, is wide, mot- 

 tled, and speckled with brown and white, with one or two 

 dashes of pure white reaching from the mouth to the edge. 

 The tentacles are in about five rows, of which the outer- 

 most are shortest and most numerous. They are ail very 

 long, flexible, and tapering; each with a delicate line of 

 brown on each side. The longitudinal plates are conspi- 

 cuously seen, on account of the general transparency of the 

 flesh, and the filaments are seen twisted up in the spaces 

 between. It is very pleasing to see in some dark corner 

 of the tank, against a dingy background of rock, a spe- 

 cimen of this, with its Medusa's head displaj'cd. Perhaps 

 it is a rather young specimen, of the lighter and almost 



