312 WHEELER. 



of the laboratory yard. On both occasions the workers formed a 

 stragghng file and were extremely timid, turning back on their trail 

 at the slightest disturbance. The typical form occurs in Southern 

 Brazil and Paraguay; the Kartabo form has the postpetiole as broad 

 as the petiole (narrower in the type), and only 1| times as long as 

 broad (1| times in the type), the sides of the petiole are longitudinally 

 rugulose, the dorsal surface of its node shining, with a few coarse 

 punctures. The antennae, head, thorax and petiole are deep red, the 

 remainder of the body and appendages yellow, the mandibles infus- 

 cated. I have compared the specimens with a small cotype of the 

 typical angnstinode from Rio Grande do Sul in my collection. 



Eciton (Acamatus) pilosum F. Smith var. beebei var. nov. 



(Fig. 1h). 



Only two foraging colonies of this ant were seen in the jungle about 

 Kartabo. July 20, Mr. Beebe found one of them near the burchelli 

 nest above described, running in a long file from which he took two 

 partially dealated males that were being conducted along by the 

 workers. On going to the spot somewhat later I captured two more 

 males, also partially dealated. The ants had their nest in a huge log 

 where it could not be reached. On Julv 21, another forav of the 

 same colony was observed but no males were seen. The workers 

 were ascending and descending a large liana and carrying to their 

 nest dozens of cocoons of some small Camponottis which apparently 

 nested in the epiphytes on one of the trees, at a considerable distance 

 from the ground. Thus laden with its prey the column resembled a 

 party of Polyergus returning from a slave-raid on Formica jvsca. 

 The second colony, observed July 28, was foraging on the ground in a 

 long column. 



On examining the worker and male specimens taken July 20, I find 

 that the former represent a variety of lyilostiiii very close to var. 

 angustius Forel, originally described from specimens taken by K. 

 Fiebrig at San Barnardino, Paraguay. Comparison with a dozen 

 cotypes of this variety in my collection shows that the Kartabo form, 

 which I call beebei, differs only in the following particulars : The color 

 of the body is even darker, being almost jet black and much darker 

 than the typical pilosum; the mandibles, cheeks and the antennal 

 funiculi are light brown throughout, whereas in angustius the upper 

 surface of the funiculi is black, the mandibles and cheeks are fuscous. 



