THE CANADIAN ENTOMOLOGIST. 301 



He calls attention to the great resemblance already noted between 

 the faunas of Europe and North America, going so far in many cases as 

 to the identity of genera and species, and this after rejecting mistaken 

 identifications on the one hand, and demonstrating the identity of Ameri- 

 can species, reputed, as new, with well-known European forms on the 

 other. His researches have given i6i species and 261 genera of European- 

 American Hemiptera, and this includes the imported and naturalized 

 forms, of which 31 have come to America from Europe, and only 2 

 have been exported to the other side of this continent. The imported 

 species, except Clinocoris lecttdarhis and Rediiviiis personatus, are all 

 Homoptera — more or less injurious to cultivated plants. Deducting 

 imported species (the number of which does not include certain forms 

 held by our entomologists to be imported because found here later than in 

 Europe, from which view Horvath differs), there are 128 species common 

 to both continents, 59 Heteroptera and 69 Homoptera. In the former he 

 lists 3 Pentatomias (or Cimicids); 9 Lygeeids ; 4 Aradids ; i Gerrid, 

 Gerris rtifosctdellatiis^ Lair.; 6 Reduviids, of which 5 are Reduvioli ; 4 

 Acanthids (or Saldids) ; 2 Anthocorids ; no less than 28 Mirids (or Cap- 

 sids ; I Notonectid and 2 Corixids. The Homoptera are mainly Jassids, 

 Cercopids, Aphids (by far the most abundant) and Coccids. 



In examining these lists one is struck by the fact that the vast 

 majority belong to the colder parts of Europe, and only 6 are from the 

 South, and also found in the Southern United Stales. Their artificial 

 spread is inadmissible, and while he does not consider theories of a great 

 continent between Europe and America, nor that the dispersal was by 

 way of Iceland and Greenland when these had a milder climate, Dr. 

 Horvath considers that the fact that the common species are also Palae- 

 arctic forms evidently shows that the dispersal was by way of Behring 

 Strait. In confirmation of this supposition we have the facl^ that five 

 species have been found only at the extreme north-west of America, and 

 that certain others have not penetrated far into the Palasarctic region, and 

 still others are common only to north-western America and north-eastern 

 Asia. 



As to the genera, he finds that of those common to the two faunas, no 

 less than 138 are of Palaearctic origin, 31 are Nearctic, 23 Holarctic, 13 

 Neotropical, 5 Oriental, 4 Ethiopian, 12 intertropical and 22 cosmopolitan. 



(2) Dr. Horvath cites six, but one is known to me positively to be a mis- 

 identification. 



