MOLLUSCA OF MICHIGAN— WALKER. 447 



as to keep it stretched tight. A sht in the rubber correspoiuUiig to the hole 

 in the can will enable one to slip the snails into the can, and the elasticity 

 of the rubber will keep them from getting out again. A few leaves should 

 be put into the cans before starting out to prevent the shells from being 

 injured by rolling around inside. As the cans become full, the leaves can 

 be removed. Several boxes and a number of vials should always be carried, 

 so that specimens from different localities may be kept separate. 



For the fluviatile species it is necessary to have a dipper and, if possible, a 

 small dredge. The dipper is made from an ordinary tin one, by removing 

 the bottom and substituting one of fine wire cloth. By removing the end 

 of the handle the dipper can be slipped on to the end of a cane or pole when 

 in use. This is useful not only for reaching the larger specimens from the 

 shore or boat, but especially for sifting the mud and sancl from the bottom, 

 where a multitude of small species live, which otherwise w^ould not be found. 

 It will be found more convenient to empty the contents of the dipper, when 

 thoroughly washed out, into a pail and carry the whole mass home before 

 undertaking to pick out the shells. If attempted in the field, many of the 

 smaller and more desirable things are apt to be overlooked. By spreading 

 the mass out in the sun for a short time it will become dry and friable so 

 that the shells can be easily separated and picked out. An ordinary read- 

 ing glass is very useful for the detection of the more minute forms in sorting 

 over such material. 



Many desirable species live in water too deep for the convenient use of 

 the dipper, and for these it is necessary to have a small dredge. One with 

 an aperture of 9 x 6 inches is as large as can satisfactorily be used by a single 

 person in a row boat. 



Care must be taken to keep the more fragile species separate from the 

 heavier ones, otherwise they are apt to be damaged in carrying the can 

 about. 



kirkland's collecting apparatus.* 



Scoop. — A common, tin, cylindrical oblique-topped flour sieve with 

 handle. Remove the wire stirring-device and solder up the holes for its 

 axis. Strengthen attachment of handle to body by soldering additional 

 braces between the two. Get more rigidity by winding brass wire around 

 body, soldering the strands from ^" to 1'' apart. 



Collecting Bag. — First: At a corset factory procure a square yard of 

 the material used for making summer corsets, with a square or triangular 

 mesh, fine enough to retain the smallest specimens and coarse enough to 

 permit escape of sand and mud. With strong linen thread make a double 

 seamed bag with rounded bottom. This bag will be approximately 12'' in 

 diameter. 



Second: Get a piece of ^''' mesh, galvanizecl-iron wire netting 11'' square, 

 and tack it with staple tacks to a wooden frame, 11" square, made of pine 

 2" wide and 1" thick. To prevent ends of wire catching in or tearing the 

 outer bag, thin strips of w^ood 1" wide are nailed around the frame so as to 

 cover wire ends. 



Make another bag of denim 18" to 20" deep, just large enough to fit the 

 wooden frame. Tack one end of this bag around the frame wdth large 

 headed tacks. 



Insert this second bag within the first and fasten the tops together with 

 four or five strong safety-pins. 



* Prepared by Dr. R. J. Kirkland of Grand Rapids, Mich. 



