212 
Psyche 
Summary 
[September 
In this paper the term “myrmecocoles” is suggested to 
cover the organisms found in the nests of ants, irrespective 
of degree of association with the host ant, viz. accidental 
occurrence to the symphiles and parasites, and a supple- 
mentary list of the myrmecocoles of Formica ulkei is given. 
Certain ecological interrelationships have been observed 
among the beetles inhabiting the nests of the mound-build- 
ing ant, Formica ulkei Emery and experiments have been 
made to determine their general behavior with respect to 
the biotic factors of enemies and food and the physical 
factors of light and moisture as well as the differential 
activity of these species under laboratory conditions. It is 
suggested that the rate and character of locomotion of 
certain myrmecocoles may be a partial criterion in de- 
termining the degree of association between the species and 
its host ant. 
Especial reference is made to the blind Leptinus testaceus 
Mull, and its behavior as possibly throwing some light 
upon its ecological status, as well as the carabid, Tachyura 
incurva (Say), and the pselaphids, Batrisodes globosus 
(Lee.) and B. denticollis Casey. 
Bibliography 
Allee, W. C. 1926, Studies in animal aggregations : causes 
and effects in land isopods. Jour. Exp. Zool., 45 :255-77. 
1927, Animal Aggregation. Quar. Rev. Biol., 2:367-98. 
Banks, Nathan, 1911, Cases of Phoresie. Ent. News, 22: 
194-6. 
Blatchley, W. S. 1910, Coleoptera or Beetles known to occur 
in Indiana. Indianapolis: Nature Pub. Co. 1386 pp. 
Brendel, Emil. 1887, Catalogue of Coleoptera collected in 
the vicinity of Peoria. Bull. Peoria Sci. Assoc., pp. 
53-63. 
