THE ANT-LOVING BEETLES. 305 



closely and rugosely punctured near base. Elytra one-half longer than wide, 

 two-thirds wider than thorax, coarsely and rather sparsely punctate, and 

 sparsely clothed with short, stiff recurved hairs. Length 1.5 mm. 



Lawrence County; rare. October 16. Taken from nest of red 

 ants beneath decaying log. 



Family X. PSELAPHIDJE. 

 The Ant-loving Beetles. 



Very small chestnut-brown, dull yellow 7 or piceous species, not 

 exceeding 3.5 mm. in length, having the body usually slightly pu- 

 bescent, head and thorax mostly narrower than elytra and abdo- 

 men ; elytra short, truncate ; abdomen convex, obtuse at tip and 

 with, half its length exposed above. They live for the most part 

 beneath bark and stones, where they feed upon Acarina and other 

 minute animal forms. Others excrete from small tufts of hairs a 

 substance of which ants are very fond, and they are therefore toler- 

 ated in numbers in the nests of these insects. They are even said 

 to be fed by the ants and to ride about on the backs of their hosts 

 when so inclined. 



The name of the family is from that of the typical genus, Pse 

 laplius, meaning "I feel my way," in allusion to the greatly de- 

 veloped palpi or "feelers," the maxillary palpi being usually 4- 

 jointed, greatly developed and of a variety of remarkable forms. 



In addition to the characters mentioned the Pselaphidae have 

 the mandibles usually broad and short, with the tips curved and 

 acute; antennas usually clavate, rarely bead-like, the number of 

 joints variable, but usually eleven ; eyes with coarse facets, some- 

 times wanting; presternum almost obsolete between the front coxae, 

 which are conical, prominent, contiguous, the cavities open behind; 

 middle coxae rounded, contiguous ; hind ones narrow, transverse, 

 usually separated; metasternum very broad, its sidepieces simple; 

 legs long, femora often club-shaped; tibiae slender and wuthout 

 spurs; tarsi usually 3- (rarely 2-) jointed; claws simple. 



Nearly 2,500 species of Pselaphidae are known, about 275 of 

 which are from North America. The more important papers treat- 

 ing of these are as follows : 



LeConte. — "On the Pselaphidae of the United States," in Bost. 

 Journ. Nat. Hist., VI, 1849, 64-110. 



Brendel, E. — "Synopsis of the Genera and Species of the Fam- 

 ily Pselaphidae," in Proc. Ent. Soc. Phil., VI. 1866. 31-38. 



