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On a New Vivarium. 

 By J. D. Hardy. 



{Read 26th November, 1880.) 



When using the ordmaiy zoophyte troughs, I have often con- 

 sidered that they had many objectionable qualities ; I therefore 

 set myself to work to see if something better could not be devised. 

 At the last general meeting Mr. Crisp brought before the notice of 

 the meeting a trough, known as " Botterill's," the existence of 

 which I was ignorant of until that time, and although there now 

 appears some similarity of construction between that and mine, I 

 venture to think that in simplicity and general usefulness (as well 

 as in the cost) that this will be found to be far su^Derior. The main 

 objections to the old Zoophyte trough were that it was necessary to 

 employ one much deeper than what was absolutely required for the 

 purpose of jjlacing the object in the water without injuring it ; 

 secondly, that when you had got the object into a good position for 

 viewing it, you had to take it out again and bottle it, if you wished 

 to carry it anywhere for exhibition or otherwise ; thirdly, the water 

 in the trough (through its being open at the top) was always more 

 or less susceptible to every movement, which caused some objects to 

 have a constantly oscillating motion ; also, the water being of a certain 

 depth, was very objectionable in using the paraboloid — also non- 

 reversible, and must be kept upright. 



Now, this Trough — or Vivarium, as I shall call it, for it is 7iot a 

 trough — will be found to obviate all these objections, besides con- 

 taining the elements of other uses and improvements. 



The cell consists of two flat pieces of clear glass, Sin. x 2in., or 

 2in. square, to the lower of which is cemented cither an indiarubber 

 or glass ring of any desired thickness ; this is covered on the upper 

 side with some adhesive substance (if necessary), or it may be 

 simply greased to render it impervious. A piece is cut out of the 

 ring at the top, about a quarter of an inch wide and funnel shaped ; 

 the upper piece of glass is then placed on the ring, and tlic whole 



