PERSECUTED AND TOLERATED GUESTS. 389 



slipping from the smooth chitinous exoskeleton. Finally she succeeded 

 in getting hold of one of the legs and carried the guest a short distance 

 in this manner, till it suddenly slipped out of her mandibles. Then 

 the ant made no further attempts to seize the beetle, but with her fore- 

 feet rolled it along for some distance, like a barrel, while it held its 

 legs completely withdrawn." Of our North American species H. 

 blanchardi is recorded by Schwarz (1890) as occurring in the nests 

 of ApJiccnogaster fulva, and H. brunneipennis as living in those of 

 Formica subsericea and exsectoides. H. horni occurs in the nests of 

 F. schaufussi, according to Wickham (1892). I have taken brunnei- 

 pennis also in the nests of F. neocinerca in Illinois. Brues (1903) 

 -records the occurrence of a new species in the nests of F . subpolita in 

 California. 



I have recently published some notes on H. brunneipennis (1908^). 

 April 12 seven of these beetles were placed in an artificial nest with a 

 number of F. subscricea workers and larva? and kept under observation 

 till June 30. Although the golden-yellow trichomes are scattered over 

 the elytra and thorax of H. brunneipennis (Fig. 229) and not collected 

 in masses on the sides and front of the thorax, as in some of the 

 species from the Western States (c. g., H. tristriatns], these structures 

 nevertheless powerfully attract the ants. The beetles run about the 

 nest with surprising agility, considering the awkward shape of their 

 body and legs, or stand motionless with the anterior part of the body 

 elevated and the fore pair of legs raised from the floor, turned forward 

 and strongly flexed at their femorotibial joints. When a beetle in this 

 position happens to be touched by the antennae of a passing ant, it 

 begins to wave its fore legs as if to attract attention. The ant stops, 

 begins to lick. the beetle or seizes it with her jaws. The body of the 

 latter, being very hard and smooth, slips from her grasp but the ant 

 redoubles her efforts. She either seizes it by one of its legs, since the 

 beetle does not feign death nor withdraw its appendages, but allows 

 itself to be carried about the nest, or she stops, seizes it with her fore 

 feet and, holding it in a vertical position, proceeds to lick its head in a 

 very quick and effusive manner. For some time the beetle keeps its 

 head withdrawn into its thorax, after the Histerid fashion, till the ant 

 stops abruptly, protrudes her tongue and regurgitates a drop of food 

 on its face. Then the beetle protrudes its head, opens its mouth, works 

 its jaws and rapidly absorbs the liquid, which sometimes floods the 

 whole cavity in the fore part of the thorax. Thereupon the ant again 

 falls to licking the beetle as if to wipe its face free from the moisture, 

 and either leaves the creature to its own devices or regurgitates another 

 drop. Again and again the licking and feeding may alternate, as if the 



