1935] 
Beetles Associated with Ants 
227 
selves they may or may not resume feeding. Holmquist 
(1928a) listed two species of earthworms in the ulkei nests, 
and since these oligochaetes are abundant in the wet soil 
of the nest rich in organic debris, they may form a part of 
the normal diet of globosus. 
Fig. 2. Diagram of some of the habitat interrelations among the 
myrmecoeoles of Formica ulkei Emery. 
When a number of these pselaphids are isolated without 
food in an artificial nest the first individuals to die are 
summarily attacked by their cannibalistic companions who 
bite and lick at the integuments and especially at the ar- 
ticular membranes. From these data it is clear that Batri- 
sodes globosus is a predator, attacking other ulkeicoles, and 
