March, 1919] A Key to Wisconsin Ants 291 



Genus Myrmica Latr.* 



1. Antennal scape with a tooth or transverse lamina at the base 



scabrinodis Nyl. and varieties. 2. 



Antennal scape without a tooth or lamina at the base, .rubra hrevinodis Emery. 



2. Color of body pale red; nest built in dry open fields 



scabrinodis var. sabiileti Emery. 



Color of body dark; antennal lamina prominent; nest built in the woods. . 

 scabrinodis schencki var. emeryana Forel. 



M. scabrinodis Nyl. 

 A palearctic species with several varieties. 



M. scabrinodis var. sabuleti Emery. 

 This is a pale red variety of the species. It nests in sandy 

 or gravelly sunny places and is often seen in attendance upon 

 aphids. 



M. scabrinodis schencki var. emeryana Forel. 

 A darker form of scabrinodis which nests in the wood. The 

 workers have a very pronounced lobe on the scape. 



M. rubra brevinodis Emery. 

 This species seems to abound in sections where the climate 

 is rather cold and is often collected at high altitudes. It is the 

 host of L. enter soni, another ant. 



Subfamily Dolichoderin.e. 



1. Epinotum strongly concave posteriorly 



Dolichoderus Lund. subgen. Hypoclinea Mayr. 



Epinotum not concave posteriorly; petiole absent or vestigial 



, Tapinoma Foerster. 



Genus Dolichoderus Lund. 

 D. (Hypoclinea) taschenbergi Mayr. var. 

 Small, rather robust, shining black ants with the posterior 

 portion of their epinotums concave. 



This species is an arboreal type and is commonly found 

 attending aphids or scales on trees. When crawling over the 

 trees, they have the habit of moving in files. 



Genus Tapinoma Foerster. 



T. sessile Say. 



The workers of this form are slender black ants that nest 



in the ground or in rotten wood. When nesting in the ground 



they construct crater-like nests. Although they feed on dead 



insects, the workers also have a fondness for attending aphids. 



* Dr. W. M. Wheeler kindly furnished the key to the species. 



