222 
Psyche 
[December 
leptinids, and has been discussed elsewhere (Park, 1929). 
These delicate animals, eyeless, extremely flattened, and of 
pale yellow color were apparently unmolested by the ulkei 
workers, but were attacked and devoured by nest preda- 
tors mentioned later. The food of this species remains 
uncertain, but as far as its presence with ulkei is con- 
cerned, it appears to be a tolerated form, one of the loricate 
synoeketes. 
Fig. 1 . Diagram of some of the food interrelations among the myrme- 
cocoles of Formica ulkei Emery. The inner circle encloses the host 
species and its food supply; the intermediate circle contains those 
species where a definite association is known to exist with the host; 
the outer circle is reserved for either accidentals or those forms 
where the relationship is still obscure. 
The arrows point to the food and away from the feeder. The 
broken line indicates regurgitation of food by the host workers. 
