AUTHOR'S TANK DESCRIBED. 363 



leavitg it to his readers to imitate the arrangements, 

 or adopt a style of their own as they may think 

 proper. 



At one time I used to make a grounding of sand, 

 but this plan is not to be recommended, even though 

 it be one highly approved of by several species of 

 crabs, &c. White pebbles do very well, but I now 

 prefer to cover the base of the tank with crushed 

 shells, washed very clean. 



The following is a sketch of one of my tanks as 

 it at present stands: 



Iii the centre of the vessel is a semi-circular arch, 

 formed of pure white Sicilian marble, which has to 

 my eye a most pleasing appearance. Around it, and 

 indeed over the entire floor of the tank, are strewn 

 chippings of the same material as the centre piece 

 itself. 1 From the arch, at certain intervals, hang 

 various sized specimens of the Mytilus edulis, which 

 have gradually advanced to their more or less ele- 

 vated positions entirely by their own unaided exer- 

 tions. Near hand a hardy A. mesembryanthemum 

 has taken up his abode, and sits with ever expanded 

 tentacles, motionless and happy. On either side of 

 the Anemone is deposited a riband of Doris spawn, 

 that undulates to and fro whenever by any chance 

 the water is in the slightest degree disturbed. Se- 



1 The arch was cut from one of the waste pieces, of which there are always a 

 large number, lying in a marble mason's yard, and cost but a few pence. The 

 4 chippings' may be had in most cases for the trouble of carrying them avvay. 



