92 THE AQUARIAN NATURALIST. 



bands of cilia are kept constantly in action, all seeming 

 to perform their duties quite irrespective of the rest. 



The tentacula of these beautiful animals are, next 

 to their cilia, the most interesting portions of their 

 structure. These organs are not always apparent, 

 but remain enclosed in the creature's body. They 

 are seldom displayed immediately after the Beroes 

 have been captured, nor when the glass vessel in which 

 they are kept is too much crowded. When, however, 

 not more than five or six are placed together, the ten- 

 tacula may be seen developed to their fullest extent, 

 frequently extending above six times the length of the 

 body of the animal. The tentacula are often pro- 

 jected from their tubes to their full extent by one 

 impulse, and the slow uncoiling of the slender ser- 

 pentine filaments from their margin is then very 

 beautiful. Indeed, it is scarcely possible to convey 

 by any description an idea of the elegance and diver- 

 sity of their forms. They seem endowed with exqui- 

 site sensibility, which, however, is not always equally 

 delicate. At times, the slightest touch will cause a 

 tentaculum to be drawn back into its sheath with a 

 sudden jerk; at other times it is apparently unfelt. 

 The Beroes never seem to be poised or supported in 

 the water by the assistance of these remarkable or- 

 gans ; but sometimes, when they are extended to the 

 bottom of the vessel, they seem to act as suckers, and 

 to form fixed points whence the animal rises and falls 

 at pleasure, appearing as if moored by these delicate 

 and novel cables. 



" Like a planet around its sun, or more exactly," 

 says Agassiz, " like the comet with its magic tail, the 



