208 
colouring, the new species is also very different, being of a brownish- 
grey mixed with black, and altogether much darker than Rhea ame- 
BN a 
Fig. 2. 
ricana. The top of the head and streak at the back of the neck in 
particular are of a deep black. 
The accompanying drawings represent (fig. 1) the head of the new 
Rhea (R. macrorhyncha) and the heads of the two other species, 
Rhea americana (fig. 2) and Rhea darwinii (fig. 3), which are given 
for the sake of comparison. 
