110 ENTOMOLOGICAL SOCIETY 



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thought that there were two primary factors in the distribution 

 of a species one, climate, the other, food. But while as a 

 general principle this appears to apply, there is sometimes a 

 great difference between species as affected by one or the other. 

 He stated that in his study of the Scolytidae and other forest 

 insects he found that some species of a genus may be restricted 

 to a given faunal zone regardless of the natural or artificial 

 distribution of the host, while others will be distributed over 

 several widely different zones of a continent and become 

 adapted to many hosts. Professor Piper said that sometimes 

 one factor determines and sometimes another. That tempera- 

 ture is not always the prime factor was well illustrated by an 

 observation on two species of spermophiles in Washington 

 State. The two species had definite ranges. When a disease 

 nearly exterminated one the other occupied the abandoned 

 range, proving that competition between the species was a 

 strong factor in determining their habitat. 



Mr. Heidemann exhibited specimens of Teraticoris hcrbat- 

 icus, a capsid described by Uhler from Labrador, and referred 

 to a lately published paper in Swedish by Prof. O. M. Renter, 

 " A North American Hemipter found in Norway," in which 

 it is stated that specimens found in Tromsoe, northern Norway, 

 proved to be in every detail identical with the species from 

 Labrador. It has nowhere else been found in the Palsearctic 

 region and the probability is that the North American species 

 was distributed over Greenland and Iceland into Norway, y 



Doctor Hopkins stated that his observations on the Scolytidae 

 led him to believe that many so-called circumpolar species are 

 distinct and that often the supposed affinities are more ap- 

 parent than real, being due to the parallel development of 

 characters under similar environments. He stated further 

 that it was not impossible or even improbable that many forms 

 of life, common to two or more countries, which are recognized 

 as species, may have had independent origin from a common 

 primitive stock. 



Mr. Van Horn exhibited adult specimens of the elaterid 

 beetle Microrrhagus pectinatus Lee. and some interesting 

 larvae which may prove to be its immature stages. The larvae 



