ECOLOGY OF ISLE ROY ALE. 325 



THE ANTS OF ISLE EOYALE, MICHIGAN. 



BY DR. WILLIAM MORTON WHEELER. 



Harvard University. 

 Subfamily Myrmicinae. 



1. Myrmica hrevmodis Emery var. canadensis Wheeler. Sev- 

 eral workers from a single colony: 61 (I, 2) H. A. Gleason. "Pound 

 on the dry rock ridges under the mats of bearberry and also excavating 

 nests in the crevices of rocks to a depth of some 8 cm." This is the com- 

 mon variety of the subspecies hrevinodis at higher elevations in Canada 

 and the Eastern States. 



2. Leptothorax acervorum canadensis Provancher. Workers from 

 three colonies: 63 (I, 2), (I, 1), 77 (I, 2), H. A. G. "Abundant inCla- 

 donia clearings and on rock ridges, running about on the surface and 

 through the thin deposits of soil. The specimens of No. 73 were from the 

 rock pools on the shore just south of Tonkin Bay." This ant, like the pre- 

 ceding, extends its range into the Northern and Eastern States, but it is 

 by no means common. It is abundant, however, at higher elevations 

 (8000-9000 ft.) in the Rocky Mountains and at lower elevations in Nova 

 Scotia. 



Subfamily Dolochoderinae. 



3. Tapinoma sessile Say. Workers from a single colony : 132 (V, 

 2) C. C. Adams, ''under Gladonia." This is the only Dolichoderine ant 

 which ascends to high latitudes and elevations. I have found it nesting 

 under stones at altitudes of over 10,000 ft. near Cripple Creek, Colorado, 

 and it is common in the Canadian zone throughout the Rocky Mountains. 

 In the Northeastern States it descends to sea-level. 



Subfamilj' Oamponotinae. 



4. Lasius niger L. var. neoniger Emerv. Workers from five col- 

 onies: 20 (I, 5) C. C. A., and 75 (I, 1), 79 "^(I, 5), 82 (I, 5), 83 (I, 5), 

 H. A. G., "Abundant on the rock ridges and jack pine ridges (I, 2, 5). 

 The nest is always constructed beneath or at the side of a flat or angular 

 stone, at a depth of one decimeter or more. A complicated system of 

 roomy galleries is excavated with passages 1..5-2.5 cm. high by 2-5 cm. 

 broad. This ant was seen to capture and kill a beetle. No. 75 H. A. G. 

 is material from the rock pools." (Gleason). 



There are in North America three distinct varieties of the circum- 

 boreal L. niger, viz., var. neoniger Emery, sitkdensis Pergande and ameri- 

 canus Emery. "The first and second have the legs and antennae of the 

 workers and females covered with suberect hairs, and the hairs on the 

 body are also conspicuously abundant. L. neoniger is small and black, 

 sitkdensis much larger and of a lighter brown or yellowish color. L. 



