162 JOHN HAMILTON, M. D. 



A study of the distribution of the species here presented must 

 have an important bearing in the study of the ancient geography of 

 the Northern Hemisphere. The large number of native species in 

 common and the intimate relationship between the Coleoptera of 

 northwestern America and northeastern Asia is brought out very 

 prominently, while on the other hand the paucity of native common 

 species on both the Atlantic coasts is as plainly presented. Both 

 Drs. LeConte and Horn have frequently adverted to this in their 

 writings, and this merely furnishes statistic proof. 



PaUeontological geography cannot be entered on here ; suffice it 

 to say that, from coleopterological considerations, the indications are 

 that Europe and America were formerly as widely separated by 

 water as they now are ; that eastern and western North America 

 were divided by water centrally (the northeastern part probably 

 submerged in whole or in part) ; that the area now occupied by 

 Behring Sea from Kamtschatka to Alaska and far west of the Aleu- 

 tian Islands was land, and possessed a more temperate climate than 

 at present. 



I cannot better close this paper than by referring to several papers 

 by Dr. LeConte relating to distribution, palaeontology, etc. : 



1. On certain Coleoptera indigenous to the eastern and western 

 continents, An. Lye. iv, 159, etc. 



2. On the parallelism, equivalents and analogues of American and 

 European, Arctic and sub-Arctic forms, etc., L. S. 239, etc. 



3. Observations, inter alia, on the much greater number of genera 

 and species common to both continents on the Pacific than on the 

 Atlantic sides, P. R. R. 1 et seq. 



4. Tables relating to transcontinental distribution, J. iv, 9 et seq. 



5. Address to the American Association for the Advancement ot 

 Science (contains much valuable palreontological matter), American 

 Naturalist, ix, 481, etc. 



My most sincere thanks are extended to Mr. W. H. Harrington 

 and Mr. F. Blanchard for manuscript records of distribution ; to 

 Dr. George H. Horn for valuable suggestions and much unrecorded 

 distribution, and especially for his kindness in supervising and cor- 

 recting the proof sheets ; and lastly to Mr. Charles S. Blake, the 

 scientific compositor, whose work has been so perfect as to scarcely 

 require correction. 



