NATURAL LOCALITIES OF BRITISH COLKOPTERA, 123 



shingle or under little heaps of refuse. Heteroccrns, and Gcori/ssus 

 with its curious coating of mud, must not be forgotten, nor must 

 Cri/ptohypnus, among the Elateridce, of which genus one or two 

 species are eagerly sought after by Scotch collectors on river- 

 banks. CiLrculionklce, too, — for example, Barynotus, — may often 

 be turned up under stones near the water's edge, and there are 

 many other species of various genera that often occur : it must, 

 however, be remembered that in windy weather large numbers of 

 beetles are blown into the water, and are carried down until they 

 find their way to the banks, where they remain for some time 

 drying, and recovering themselves before starting off afresh. 



Before leaving this part of our subject, the river-bank 

 Hemiptera, especially Salda, require a passing mention ; and 

 the Hydrodromica, Velia, Mesovelia, MicrovcUa, a,nd Hydrometra, 

 though perhaps hardly true bank-insects, cannot well be placed 

 in any other connection. 



Beetles can endure immersion in water for a very long 

 period, considering their structure. Nothing surprised the 

 Americans more in the history of the Colorado beetle than the 

 fact that not only rivers proved no obstacle to its progress, but 

 that it even managed to cross Lake Michigan and establish 

 itself firmly on the other side. It is owing to this fact, added 

 to the fact that the hard integuments of beetles are not easily 

 damaged, that makes flood-collecting so profitable. 



When a river overflows its banks it seems to sweep all the 

 beetles of the district down with it, and to concentrate them in 

 some few localities : if a river can be watched just as it rises, 

 good species may often be obtained on the spot. Dr. Power 

 once took Bembidium prasinum in abundance in this way. When 

 once it has overflowed its banks, the direction of the wind should 

 be noted, and a good collection of refuse and debris be gathered 

 from under the railings, hedges, or banks against which it has 

 been drifted. The observation of the wind is important, as 

 anyone who knows the ground will by it be enabled at once to 

 tell where he will find an accumulation. No one who has not 

 tried flood-collecting can have any idea of the enormous quantities 

 of beetles that one bag of rubbish will produce ; of course a large 

 majority are very common species, but it is very seldom that a 

 flood does not produce some good ones. I have been very 

 successful in large floods of the Trent, at Repton ; in fact, the 



