FORMIC ABLE. 



187 



An allied genus is Pseudomyrma, P. bicolor Guerin (Fig. 

 117) is found in Central America. P.Jlavidula Smith, found in 

 Central and South America, in Mexico lives, according to 

 Sumichrast, within the spines which arm the 

 stems of certain species of Mimosa. These 

 spines, fixed in pairs upon the branches, are 

 pierced near the end by a hole (Fig. 118), 

 which serves for the entrance and exit of the 

 ants. 



The genus (Ecodoma differs from Atta in 

 having the thorax armed with spines. (E. Fig. no. 



Mexlcana Smith (Figs. 119, female; 120, worker major) is 

 abundant on the Gulf Coast of Mexico. In many places, ac- 

 cording to Sumichrast, the natives eat the females after hav- 

 ing detached the thorax. The intelligence of these 

 ants is wonderful. They are seen in immense num- 

 bers transporting leaves. Sumichrast states that 

 "the ground at the foot of the tree, where a troop of 

 these ' arrieras,' or workers, is assembled for despoil- 

 ing it of its leaves, is ordinarily strewn with frag- 

 ments cut off with the greatest precision. And if the 

 Fig. 117. tree is not too lofty, one can satisfy himself that a 

 party of foragers, which have climbed the tree, occupies itself 

 wholly in the labor of cutting them off, while at the foot of 

 the tree are the carriers which make the journeys between the 

 tree and the nest. This manage- 

 ment, which indicates among these a ._ 

 insects a rare degree of intelligence, 

 is, perhaps, not a constant and in- 

 variable practice, but it is an incon- 

 testable fact, and one which can be 

 constantly proved." 



'.' It is specially in the argillaceous 

 countries that the GEcodonias build 

 their enormous formicaries, so that 

 one perceives them from afar by the Fig. us. 



projection which they form above the level of the soil, as 

 well as by the absence of vegetation in their immediate 

 neighborhood. These nests occupy a surface of many square 



