BIOLOGICAL PAPERS. 137 



A PRELIMIXARY LIST OF AXIS FROM ILLINOIS. 



By Maurice Cole Taxouary, 

 L'niversity of Illinois. L'rbana. 



Some time ago I began work on the life history and ecolog}- of 

 our common corn-field ant, Lasius niger var. americanus. At the 

 time I did not expect to study ants from the systematic standpoint, 

 but on numerous field trips in search of colonies of L. americanus, 

 I collected a great many ants belonging to other species, and was 

 thus naturally led to take up a study of the occurrence and distri- 

 bution of the various species of ants. 



The following list is not assumed to be by any means complete 

 for the ants of Illinois. In fact, the object of this paper is not 

 so much to list the species already collected as to secure any possi- 

 ble co-operation on the part of members of the Academy in 

 obtaining material for identification, and data from different parts 

 of the state. As I understand it. one of the objects of this Acad- 

 emy is to enable investigators working in different parts of the 

 state, especially those working on ecological and distributional 

 problems, to co-operate in their work in such a way as to bring 

 about the greatest mutual benefit. As a matter of fact, a certain 

 amount of co-operation is necessary in order to work up the dis- 

 tribution of species over an area of any considerable extent. 



The following list of ants I obtained from three sources : 



(1) my own collection, containing fifty-one species from this state ; 



(2) from the collections of the Illinois State Laboratory of Nat- 

 ural History [including the Nason collection, the ants of which 

 were determined by Prof. W. ^I. Wheeler] ; and (3) the last thir- 

 teen species were kindly added by Prof. W. M. Wheeler from the 

 list of species which he has taken in Illinois. Some of the ants 

 of the State Laboratory collections were determined a nmnber 

 of years ago by Pergande. but the bulk of the material is as yet 

 undetermined. 



Subfamily Ponerix.e. 

 This subfamily is represented by two species belonging to dif- 

 ferent genera. 



1. Stigmatomma paUipes Haldeman. 



2. Poncra coarctata Latreille. 



These two species are the most primitive of our ants, and 

 as a rule are found in rather low. moist situations. Their colonies 

 are always small, most of them containing less than a dozen indi- 

 viduals. 



