THE ANT-LOVIN-G 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, stifC recurved hairs. Length 1.5 mm. 



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

 ants beneath decaying- log. 



Family X. PSELAPHID.<S:. 



The Ant-loving Beetles. 



Very small chestnut-brown, dull yellow 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 ston&s, 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 thej' 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 

 laphus, 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 Pselaphidns have 

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

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

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

 times wanting; prosternum almost obsolete between the front coxse, 

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

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

 usually separated; metastemum very broad, its sidepieces simple; 

 legs long, femora often club-shaped ; tibife slender and without 

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



Nearly 2,500 species of Pselaphida^ are known, about 275 of 

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

 ing of these are as follows : 



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

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



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

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



