informative contributors the following authors may be mentioned: Lewis 

 (1866 and 1868), Wetherby (1882), Dall (1892), Call (1898), Walker 

 (1902), Ortmann (1911), H. H. Smith (1912), and F. C. Baker (1921). 

 Modern collectors follow more or less the general methods which were 

 tried and proved adequate by their predecessors. In the following account 

 a summary of the methods now generally accepted will be given and 

 whenever possible suggestions will be made which might show improve- 

 ment upon earlier techniques. 



One of the first problems that confronts a collector is the selection of 

 a suitable region in which to collect. In the United States we are fortunate 

 because the Mississippi River and its major tributaries, the Tennessee, 

 Cumberland, and others, offer unusual opportunities for those interested 

 in collecting mussels. No other region in the world produces as many 

 species of naiades as are found in drainages of the eastern half of the 

 United States. With the many good roads and the ready use of the auto- 

 mobile, regions formerly quite inaccessible are now open to those who find 

 pleasure in gathering specimens and contributing to malacology. The best 

 collecting grounds are found in limestone regions, but there are large 

 portions of drainages in non-calcareous areas which are much in need of 

 careful survey work. It should also be emphasized that many productive 

 streams are being contaminated by man so rapidly that there is an imme- 

 diate necessity for collecting in some places. It is important that a fauna 

 be known before radical changes are brought about. 



Mussel collecting is usually most successful during periods when 

 streams are low. In this respect gathering naiades differs from land shell 

 collecting. Generally there are certain seasons within areas when optimum 

 field conditions exist. In the Great Lakes region low water stages are found 

 in streams between August and October, and occasionally similar dry 

 periods occur in May. In Alabama and western Georgia the dry seasons 

 often appear during these same periods. Along the southeast coast however, 

 the hurricane season frequently brings torrential rains so that late spring 

 is often the best time for collecting in the rivers there. In small tributaries 

 these matters are naturally of least significance, but they are of greatest 

 importance for work to be done in the larger rivers. Consequently, it is 

 very essential for successful field work that one select a season within an 

 area when the streams are at their lowest possible water level. 



Mussels inhabit streams and lakes, but there are usually fewer species 

 in lakes. With the exception of large lakes, such as Lake Erie, the number 

 of species inhabiting a lake is directly proportional to the amount of stream 

 influence in such a body. In other words, small land-locked lakes have 

 fewer species than river- lakes. Rivers harbor many species, the number 

 depending entirely on the physiographic province to which the drainage 

 belongs. One may collect as many as 50 species of mussels from portions 

 of certain streams in Tennessee, while similar bodies in Alabama and 

 Michigan may yield only half that number. 



In streams mussels are often found most abundant on shoals where 

 they live imbedded in the gravel, sand, or mud of the bottom. There is 



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