74 Journal New York Entomological Society. [Vol. xvi. 



Then the ant had to release its hold. Sometimes it continued 

 to gnaw at the exposed abdomen, elytra or legs, but sooner or later 

 it left the beetle to its own devices. The creature then remained 

 for hours in somnolent quiescence till some enterprising ant would 

 pull it out of its ostrich-like concealment by one of its hind legs and 

 the gnawing at the posterior thoracic angles and the march of the 

 beetle around the nest would recommence. 



The beetles were observed daily for several weeks. At times I 

 was inclined to believe that the ants had grown accustomed to their 

 presence and were beginning to tolerate them with indifference, but 

 closer observation showed that whenever the beetles left their retreat 

 and wandered about the nest they were sure to be assaulted by a few of 

 the ants and to have their thoracic angles gnawed till they again 

 succeeded in concealing themselves. This behavior on the part of 

 the ants continued without modification till June 10 and 13, when 

 the two beetles died and were placed on the refuse heap by the integra 

 workers. 



A specimen of C. castanece was also placed in a nest of F. subsericea. 

 Though this ant has a much more cowardly disposition than F. i?itegra, 

 it nevertheless attacked the beetle as soon as it spread its legs and pro- 

 ceeded to move about the nest. There was the same gnawing at the 

 posterior thoracic angles as exhibited by integra, but more pulling at 

 the beetle's legs. The subsericea workers treated the beetle much as 

 they treat an alien queen : each seized a leg and then, fixing its claws 

 in the towelling or sponge of the nest, began to pull. As the mandi- 

 bles of subsericea- are weaker than those of integra, there was even 

 less danger of injury to the beetle, which dragged the ant along till it 

 found a corner in which it could bury its head and thorax and enjoy 

 a spell of immunity from their attacks. 



The imaginal Creviastochili seem to require no food. At any rate, 

 I have never seen them eating any substances in the nests or being 

 fed by the ants, although I have kept them under observation from 

 three to seven weeks. Some of the nests in which they were confined 

 contained ants' eggs and young larvae, but these were completely 

 ignored by the beetles. In the natural nests the latter are sometimes 

 present in much greater numbers than is suggested by Hamilton's 

 statement above quoted. April 27, 1907, at Newfoundland, N. J., 

 Mr. Wm. T. Davis and I took from a single nest of F. schaujussi 24 

 Cremastochid, belonging to two species, castanece and canaliculaius. 



