ANTS AND PLANT-STRUCTURE 395 



flowers solitary, rather large, terminal or axillary, 

 rose (turning red) ; hairs of stem, leaves, etc., 

 spreading, more copious than in Tococa, and red 

 or crimson, corresponding curiously with the colour 

 of the minute ants of that viciously-stinging tribe 

 called " Formiguinhas de fogo " (Little Fire-Ants)- 

 which inhabit the sacs, and also make covered ways 

 of intercommunication along the outside of the 

 stem and branches a precaution I have rarely 

 noted among the Tococa-dwellers. 



Myrmidone rotuudifolia, sp. n., grows in caatingas 

 in the lower angle of the confluence of the Rio 

 Negro and Casiquiari. It is only 3 feet high, 

 and has crowded, subunequal leaves, the larger of 

 each pair 3^- inches long, orbicular! -panduriform, 

 cordate at the base, where there is a large sac ; 

 while the smaller leaf is orbiculari- cordate and 

 mostly (but not always) has no sac. 



Majeta guiancnsis, Aubl., has very much the 

 habit of the Myrmidones, but it has also fistulose 

 branches swollen at the nodes, so that the inhabitants 

 have an inner way of communication between the 



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sacs at the base of the larger of each pair of sessile 

 leaves. 



Calopliysa tococoida, DC., is a slender shrub with 

 thin hairy leaves, the larger leaf of each pair having 

 a large bifid sac at the base of the petiole ; but the 

 frequent presence of a narro\v wing connecting 

 the leaf with the sac proves that the latter belongs 

 really to the lamina (as in the Tococas) and that 

 the leaf is sessile. 



Examples of sac-like ant-dwellings exist in the 

 leaves of plants of other orders, so like those already 

 described in Melastomes, that it is scarcely worth 



