532 



MR. P. L. SCLATER ON THE 



[June 15, 



6. Mergus octosetaceus, Vieill. Brazilian Merganser. 

 Mergus octosetaceus, Scl. et Salv. P. Z. S. 1876, p. 409. 

 Hab. Interior of Brazil. 

 Rare even in the best-stocked collections, and not known alive. 



K. Conclusions as to Introduction. 



It would appear, therefore, from the foregoing list (as will be 

 seen more closely by the subjoined summary) that out of about 

 176 certainly known species of Anatidse, 94, or more than one half, 

 have been at some time or other acquired in the living state, and 

 shown in zoological gardens or other such places, and that of these 

 50 have propagated in captivity. 



Table I. Showing the numbers of introduced Anatidse. 



L. Remarks on the Geographical Distribution of the 



Anatid^. 



I will conclude with a few remarks upon the geographical dis- 

 tribution of the Anatidse. 



In treating of this part of the subject I find it impossible to sepa- 

 rate conveniently the Palaearctic and Nearctic species. So many of 

 the high northern species are circumpolar, or common to both con- 

 tinents, and so many other of the Palaearctic species have closely 

 allied (in some cases barely separable) representatives in the Nearctic 

 area, that it is much more natural to unite these categories into 

 one group as "Arctic Anatidse." Adding to this the other four 

 generally recognized divisions, we shall find the Anatidse come out 

 somewhat as follows, in five great geographical groups : — 



