H. J. WADDINGTON ON MARINE AQUARIA. 245 



to keep, and which has gone the round of four or five Aquaria 

 before it was suited. I am speaking of Aquaria holding about 

 eight or ten gallons of water ; doubtless larger ones of twenty or 

 twenty-five gallons capacity would offer better conditions, but as 

 the various forms of Actinia are found in various circumstances, it 

 is possible that the presence of some may be inimical to the well- 

 being of others, and that they would prefer their room to their 

 company. 



The varieties of Sagartia do very well together, but Actinolobus 

 dianthus often appears very restless in the same aquarium. I have 

 succeeded in keeping Tealia crassicornis for some months in perfect 

 condition with Anthea Cereus, the former requiring a bed of sandy 

 shingle with pieces of rock interspersed against which they lodge. 

 The Anthea has remained on the rock without showing any dis- 

 position to roam. The quantity of anemones that may be kept 

 depends very much upon the conditions of the aquarium. I have 

 seen a small one holding about a gallon of water which contained 

 eight or ten anemones, consisting of Dianthus, Bunodes, and 

 Mesembryanthemum, which, when fully expanded, covered the 

 bottom, and all thoroughly vigorous, but this was arrived at by 

 considerable attention. 



For feeding Actinia I invariably use oyster, and this food is 

 suitable even for the very smallest. For some time I hesitated 

 about keeping Corynactis on account of the supposed difficulty in 

 feeding them, but I have since found that they are readily fed 

 by very small pieces of oyster held to the tentacles on the point of 

 a stick ; this they take greedily if in a healthy condition, and the 

 same holds good for Actinia smaller than these, for the younger 

 they are the more readily do they seize the food offered them. 

 The feeding of other animal life in Aquaria presents little difficulty, 

 as there are few forms for which some method may not be devised. 

 Hydra tuba I have fed by removing the stone on which they were 

 fixed to a small vessel of water, reversing the usual position and 

 smearing the Hydra with oyster made into a pulp. After an hour 

 or so the stone is passed to and fro in the water to detach any 

 oyster which has not been grasped and then replaced in its usual 

 position. Where it is impossible to use oyster in feeding, con- 

 densing light by a bull's eye in the neighbourhood of an animal 

 will attract Entomostraca, and thus give a better chance of food, 

 while if it be desired to feed Entomostraca, Rotiferas, and Infusoria 



