300 THE AQUARIAN NATURALIST. 



account it is often constructed horizontally, or built 

 against some foreign substance for support. 



Some of the Terebellse, more especially the species 

 under consideration,, are endowed with the faculty of 

 emitting a brilliant phosphorescence, but it is rarely 

 displayed. 



When this occurs, it is apparently the result of re- 

 straint or suifering. Flashes were emitted by a small 

 specimen which had left its tube, on transferring it 

 to a different vessel : on replenishing the latter with 

 water, a most copious bright blue refulgence, inter- 

 mingled w r ith a reddish flame, streamed from the ten- 

 tacula and other organs. Apparently the phospho- 

 rescent property is diffused over the body, and in 

 the case above mentioned the coruscations evidently 

 attended violence. 



TEREBELLA CONCHILEGA. " The Shell-binder" 



A third species of Terebella, the TEREBELLA CON- 

 CHILEGA, or SHELL-BINDER, is another beautiful and 

 interesting inhabitant of the aquarium. This elegant 

 Annelide, as its name imports, constructs a dwelling 

 exclusively of comminuted shell, in preference to all 

 other materials. In the natural state it generally 

 takes shelter within some capacious empty shell, such 

 as a valve of the Venus islandica, there to establish 

 its edifice. On all occasions this tube is formed of 

 irregular and unequal fragments, and lined with a 

 silk-like exudation from the body of the animal. 



This Terebella may be induced to exercise its archi- 

 tectural faculties by diminishing the light during the 



