484 WHEELER. 



Neomyrvia, Symmyrmica and Myrmecocystus) and seven are peculiarly 

 eastern (Bothriomyrmex, Hypoclinea, Strumigenys, Epoecus, Dicho- 

 thorax, Harpagoxenus and Brachymyrmex). Moreover certain genera 

 are almost exclusively western or eastern. Pogonomyrmex e. g., 

 represented by numerous species in the Southwestern States has only 

 one species (P. badius) in the Southeastern States, and Proceratium 

 and Sysphinda are at any rate very largely confined to the East. 



The great majority of the forms recorded in the tables are undoubt- 

 edly peculiar to the Transition Zone. Only the following would seem 

 to belong to the Canadian, or boreal fauna: 



Myrmica brevinodis vars. sidcinodoides, canadensis, and frigida, 



M. scabrinodis subsp. lobicornis var. glacialis, 



Leptothorax acervorum subsp. canadensis and its vars. and the subsp. 



cra^sipilis, 

 L. muscorum and its vars., 

 L. provancheri, 



L. emersoni and its subspecies, 

 Stenamma nearcticum, 

 S brevicorne, its subspecies and varieties, 

 Lasins niger var. sitkaensis, ' . 

 L. fiavus subsp. claripennis, 

 L. umbratus subsp. subumhraius, 

 Formica bradleyi, 



F. sanguinea and subsp. subnuda and aserva, 

 F. rufa obscuripes and its var. melanotica, 

 F. truncicola and its subspecies and varieties, 

 F. whymperi and its varieties, 

 F. dakotensis and its varieties, 

 F. ulkei, 

 F. fusca and its varieties neorufibarbis, marcida, subaenescens, 



argentea, gelida and algida and the subsp. pruinosa, 

 F. hewitti, 



F. cinerea var. altipetens and canadensis, 

 F. neogagates, its subspecies and var. vetula, 

 Camponotus laevigatus, 

 C. herculeanus var. whymperi and subsp. ligniperda var. novebora- 



censis. 



Most of these are what the Germans would call " stenotherm kalte- 

 liebend" (stenothermal psychrophilous). Some of them, however, 

 and especially those common to the four regions of the tables, are 



