XXIV 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. 
My7^midone rotiindifolia, 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 ^\ inches long, orbiculari-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 guianensis, 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 
sacs at the base of the larger of each pair of sessile 
leaves. 
Calophysa 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 narrow 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 
