IV. 



GENERAL REMARKS UPON THE COLEOPTERA OF LAKE 



SUPERIOR. 



' BYJOHNL. LECONTE, M. D. 



The materials which form the basis of the present catalogue, were 

 not altogether derived from explorations made during the expedition 

 which produced this volume. Thej embrace the results of my col- 

 lections during three journeys made to Lake Superior, and were 

 procured at various points around the entire circumference of that 

 sheet of Avater, and during various months from June to October. 



The distribution of species does not appear to differ materially on 

 the two sides of the lake : nevertheless many species occurred on 

 the north shore, which were not found on Point Kewenaw, while 

 many water beetles were taken at the last mentioned place, which 

 were not seen during the present voyage. Still in each case the 

 delay at particular localities was so short, that necessarily many 

 'even of the most common species would be overlooked. We may 

 therefore conclude, that although the evidence is not yet sufficient to 

 enable us precisely to distinguish between the products of the differ- 

 ent portions of the Lake Superior region, we still have abundant 

 material to give a tolerably complete conspectus of the character of 

 the entire coleopterous fauna. 



The whole country being still almost in a primitive condition, the 

 specimens are equally distributed throughout a large space : the 

 woods will not therefore be found very productive to the collector. 

 In fact nearly all the species were found adjacent to small streams ; 

 or else they were driven on shore, particularly on sand beaches, by 

 the winds and waves after being drowned in the lake. So produc- 

 tive was the last method of collecting, that on one occasion more 



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