182 HY3IENOPTERA. 



The genus Ponera is found disti'ibuted throughout the 

 tropics. Tlie females and workers are armed vvitli spines ; the 

 abdomen is elongated, the segments more or less diminished 

 in size, the first comparatively large and often cubical. The 

 legs are slender. P. ferrnginea Smith is a Mexican species. 



The allied genus Odontomachus springs like some leaping 

 spiders. It uses for this purpose its unusually long mandibles, 

 which are bent at right angles. 0. clarus Koger lives in Texas. 



Formica includes the tj'pical species of ants. Over two hun- 

 dred species of this genus have been already described. The 

 body is unarmed. The abdomen is short, oval or spherical, 

 the scale-like first segment being lenticular in form, with a 

 sharp upper edge. The subcostal cell of the fore-wings ends in 

 a point. Formica scmguinea Latr. is one of our most abundant 

 species, making hillocks of sand or clay, according to the nature 

 of the ground. From the formicary walks, and underground 

 galleries, radiate in all directions. This species has been 'ob- 

 served making forays upon each others colonies. We have 

 found a variety of this species in Labrador, where it is com- 

 mon. It does not throw up hillocks, but tunnels the earth. 



This species has been observed in Europe by P. Iluber, to 

 go on slave expeditions. They attack a " negro-colonj^ " be- 

 longing to a smaller black species, pillaging the nest, and carry- 

 ing olf merely the larvas and pupoe. The victors educate them 

 in their own nests, and on arriving at maturity the negroes take 

 the; entire care of the colony. Polyergus rufescens is also a slave- 

 making ant, and " Latreillc very justly observes that it is physi- 

 cally impossible for the rufescent ants {Polyergus rufescens), 

 on account of the form of their jaws, and the accessory parts of 

 their mouth, either to prepare habitations for their family, 

 to procure food, or to feed them." Formica savgimiea sallies 

 forth in immensely long columns to attack the negTo ant. Hu- 

 ber states that only fixe or six of these fora3s are made within 

 a period of a month, at other seasons they remain at peace. 

 Iluber found that the slave-making Polyergus rufescens when 

 left to themselves perish from pure laziness. They are waited 

 upon and fed by their slaves, and when the}- are taken away, their 

 masters perish miserably. Sometimes they are known to labor, 

 and were once observed to carry their slaves to a spot chosen 



