1871.] DR. R. O. CUNNINGHAM ON RHEA. 105 



The following papers were read : — 



1. Notes on some points in the Osteology of Rhea americana 

 and Rhea darwinii. By Robert O. Cunningham, M.D., 

 F.L.S., C.M.Z.S. 



[Received January 2, 1871.] 

 (Plates VI. & VI a .) 



Three distinct species of American Ostrich (the Rhea americana, 

 R. darwinii, andiZ. macrorhynchd) are at the present time recognized 

 by ornithologists. The first of these, which, it is almost unnecessary 

 to state, was for a long period the only species of the genus known, 

 appears to possess the widest geographical range, extending, if I am 

 not mistaken, from Bolivia, Paraguay, and South Brazil, at least as 

 far south as the Strait of Magellan*, a space of upwards of thirty 

 degrees. The second was first scientifically described by Mr. Gould, 

 in the 'Proceedings' of this Society for 1837, from a specimen pro- 

 cured by Mr. Darwin at Port Desire, on the east coast of Patagonia, 

 and probably extends from the Strait of Magellan to the Rio Negro, 

 the boundary-line between Patagonia and the Argentine Republic ; 

 while for our knowledge of the third, the locality of which is, 

 I believe, as yet undetermined, we are indebted to Mr. Sclater's 

 finely illustrated article on the Struthious birds living in the 

 Society's gardens, published in the fourth volume of the Society's 

 1 Transactions.' In that valuable contribution to our knowledge of 

 the Struthionidae, its author has briefly pointed out several very well- 

 marked points of distinction between the three species ; but con- 

 cerning these I need not occupy the time of the Society, as they 

 are doubtless well-known to the generality of those who are now 

 present. 



I may therefore pass on to remark that, in assigning such an ex- 

 tensive range as I have above indicated to the Rhea americana, I 

 am aware that my views on the subject are in conflict with the 

 expressed opinions of a highly distinguished authority (Mr. Dar- 

 win), who fixes the southern boundary of this bird at a little to the 

 south of the Rio Negro, observing that R. darwinii takes its place 

 in Southern Patagonia. I can, however, positively assert that R. 

 americana extends as far south as the Strait of Magellan, inhabiting 

 the same tracts of country as the latter species ; for in the course of 

 my sojourn in the eastern portion of the Strait, I had opportunities 

 of seeing a considerable number of recently killed specimens in the 

 possession of the Patagonian Indians ; and, although I do not recol- 

 lect having observed any examples of Rhea darwinii in the flesh, I 



* That a species of Rhea occurs to the south of the Strait, in the large 

 eastern island of Tierra del Fuego, the northern portion of which is almost 

 identical in its climate and physical characters with those of Eastern Patagonia, 

 may be regarded as certain ; but whether it be referable to the R. americana or 

 R. darwinii I am unable to state. 



