Sterki: Collecting Sph.eriid.e. 481 



up with a knife-blade, or to cut off pieces of the plants with the snails 

 on them. 



With the net the surface-layer of the bottom in pools and streams is 

 carefully scooped or scraped up, and when a good quantity is gathered 

 the net is shaken in the water, dipped repeatedly to the rim, and 

 worked with the hand to wash out mud and fine sand. Of the 

 coarser material, plants, debris, etc., handful after handful is taken 

 from the top, while the net is held in the water to near its rim, washed, 

 shaken, then looked over and thrown away. The remaining finer 

 material, generally a small quantity, with the moUusks, is then put 

 into some receptacle, best a muslin sack. Haul after haul is made from 

 a place, and then a label is added to the "washings," noting the place, 

 its nature, and the date. 



Where there are thick, tangled masses of plants, like Potamogeton, 

 Ceratophyllum, Philotria, Vallisneria, etc., along the shores of ponds, 

 small lakes, or bays, the plants may be pulled out with a rake, slowly 

 and carefully, put into a wash-tub, if within reach, and washed out 

 there. After a number of hauls the water is poured off and the 

 settlings are put in the net to be washed free from mud and tine sand. 

 A large sack mounted on a wire ring or hoop and supported by a few 

 forked sticks, hanging in the water, is also serviceable and more 

 easily carried along than a tub. Even a hole dug in the ground at the 

 water's edge will answer the purpose. After a place has been raked 

 over the net may be used to gather what has dropped to the bottom. 



At similar places away from shore collecting is done from a boat 

 or launch. The net is driven and swung through the masses of plants 

 and over the bottom, where it can be reached. Good results may be 

 obtained in this way; but, where there is an old accumulation of 

 muck, mollusks are generally scarce. Where a spring or brook enters 

 a lake or pond the harvest will usually be rich, and such places may 

 be more easily accessible from a boat than by wading out from the 

 shore. 



For collecting in water about four to eight feet deep the net may be 

 tied to a long pole; a dredge is preferable, but cannot be used where 

 the bottom is obstructed by plants, pieces of wood, etc. In deeper 

 water dredging is the only means for collecting, and should be used 

 more extensively. A small dredge can easily be made of a metal 

 frame two to three feet long and about one foot wide, or larger, with 

 a burlap sack attached, preferably protected by outer flaps of leather 



