176 TWELFTH ANNUAL REPORT. 



CHAPTER IV. 



COLLECTING, PRESERVATION AND MISCELLANEOUS 



NOTES. 



The appliances employed in the capture and study of Entomo- 

 straca are, in the main, those employed by the student of aquatic 

 vegetation. The first in order of importance is the hand-net and 

 its accompaniment, long rubber boots, such as cover the entire 

 leg being preferable. Thus equipped, the student can collect by 

 far the greater numbe* of fresh- water Crustacea. The net is best 

 made by obtaining an ordinary gaff or dipping net of extra 

 strength but small size. If jointed, the ferrule must be unusually 

 strong, not, indeed, because of the weight or activity of the prizes, 

 but because it is often necessary to lift a net full of water, which is 

 a greater strain than the strongest fish would produce in a net 

 with open meshes. The ring of such a net is furnished with a me- 

 dium-sized bag of some porous but still rather close fabric. The 

 writer usually uses for this purpose the thinner variety of flour 

 sacking. This material fulls a little when wet, and permits the 

 water to pass rather too slowly, but this is a good fault. The net 

 is used in shallow water and among weeds. After the net has 

 been repeatedly filled and permitted to drain nearly empty, the 

 bottom of the net is seized and the small remaining amount of 

 water is thrown by a dexterous movement of the hand into a large- 

 mouthed jar, several of which are needed. By this method the ani- 

 mals can be secured in any desired degree of concentration, so to 

 speak, provided care is taken to avoid fouling the net with fine 

 mud or debris. A single jar should usually contain only a gather- 

 ing from a single locality. In case the collection is not to be ex- 

 amined at once, the gathering, which must now be quite free from 

 admixture of mud and filth, is concentrated as much as possible, 



