Mollusks. 5703 



small volume of water contained in the aquarium, these effects are 

 rapidly produced. 



FOOD. 



As many persons, to whom those interested in these matters have 

 naturally looked for instruction, have decried the idea of feeding, it 

 will be necessary to offer a few remarks on that point. How crea- 

 tures so voracious as most of the denizens of the water are, both fresh 

 and marine, are to thrive without food, is a question it would be diffi- 

 cult to solve : common sense would say they must gradually decrease 

 in size, and ultimately die from starvation. The food employed 

 should be in accordance with the habits of the fish, &c. ; for the 

 vegetable and mud feeders, vermicelli crushed small, with now and 

 then a little animal food, as worms, small shreds of meat, rasped 

 boiled liver, and the like ; for the marine creatures, raw meat dried in 

 the sun, and moistened when used, answers very well. Oyster, mus- 

 sel, cockle, raw fish, shrimps, and the like matters may be employed ; 

 these should be cut or pulled into very small pieces, and never more 

 given than they can at once appropriate; and if rejected .by one it 

 should be transferred to another, or removed from the tank. In the 

 case of Actinia, they require, from their fixed position, that the 

 food should be guided to their tentacles; and if the animal food, of 

 whatever kind, is soaked in a little water, and the water thus impreg- 

 nated with animal fluids be dropped in moderate quantity into the 

 tank, it will afford food for the small Entomostraca, and smaller 

 creatures with which the water abounds, and which constitute the 

 food for many of them. 



A few observations were also made on the construction of a micro- 

 scope for the purpose of employment in connexion with the aquarium, 

 and the method in which such an instrument could be used. 



The Mollusca of the Firth of Clyde. 

 By the Rev. Alfred Merle Norman, B.A. 



The notes which have hitherto appeared in the pages of the 

 1 Zoologist ' on our Marine Invertebrata have been but few and 

 far between. There have been admirable papers by Mr. Gordon on 

 the Zoology of the Moray Firth, and a few others on a less extensive 



