FOllMICARIiE. 181 



and contain many thousand individuals. Ants also build 

 nests of clay or miid, and inhabit hollow trees. They enjoy 

 feeding upon the sweets of flowers and the honey of the Plant- 

 lice, which they domesticate in their nests. Several species of 

 beetles, including some of the StapJiylinidce , take up their 

 abode in ants' nests. Ants are useful as scavengers, feeding 

 on decaying animal matter. A good method of obtaining the 

 skeletons of the smaller animals, is to place them on a densely 

 populated ant-hill. The habits of the ants, their economy and 

 slave-making habits, are described in the works of Huber, La- 

 treille, and Kirby -and Spence. 



Upwards of a thousand species of ants have already been 

 described ; those of this country have still to be monographed. 



The first group of this extensive family consists of Dorylus 

 and its allies, and Formica and the neighboring genera, all of 

 which are distinguished by having only the first abdominal seg- 

 ment contracted, while in the second group {Myrmicarice) , the 

 two basal rings are contracted into knot-like segments. 



The genus Dorylus was, by Latreille, Klug, and others, in- 

 cluded in the Mutillarics . The head is very short, the 

 ocelli are large and globular. The thorax and abdomen are 

 elongated, the last is cylindrical, with a small, round, basal 

 joint. The legs are short, with broad compressed femora and 

 feather-like tarsi. In the wings the outer subcostal cells are 

 wanting. The females are not yet known. Mr. F. Smith says 

 that Dorylus was found by Hon. W. Elliot to live in the man- 

 ner of ants, under the stone foundation of a house in India. 

 The society was very numerous. The difference in size of the 

 male and worker is very remarkable. The males are of large 

 size and are found in tropical Asia and Africa. 



Typlilojpone is an allied genus. T. ijcdlijjes Haldeman is 

 found in Pennsylvania. 



To the genus Anomma belong the Driver-ants of Western 

 Africa. Thej- march in vast armies, driving everything before 

 them, so formidable are they from their numbers and bite, 

 though they are of small size. They cross streams, bridging 

 them by their interlocked bodies. Only the workers are known. 

 Two species only, A. Burmeisteri Shuckard, and A. arcens 

 Westwood, are described from near Cape Palmas, West Africa, 



