446 Mr. J. H. Gurney's Notes on 



Yarkand ' under the name of Faico hendei'soni Heu- 



dersou's Falcon was found by us wherever we went, from 

 Kiachta down to the sources of the Yantze-kiang." 



At the same time it should be noted, that Prjevalsky, in 

 this expedition, obtained only four specimens, the youngest 

 of which, as appears from his description of it, had not yet 

 fully attained the distinctive plumage of G. mUvipes. 



It should also be borne in mind that M. David, whose 

 extensive ornithological explorations in Northern China 

 attach very great weight to his testimony, apparently alludes 

 under the head of Falco saker to a Falcon in the ordi- 

 nary Saker plumage, and not in the G. milvipes dress, but 

 with '' taches ovales " on the outer webs of the rectrices, in 

 the following words : — " Je Fai rencontre frequemment en 

 Mongolie, ainsi qu^'a Pekin, au Chensi et dans le Setchuan"'*. 

 It is, however, probable that if G. saker and G. milvipes 

 are really distinct species, they are nearly, if not quite, un- 

 distinguishable in their first plumage ; and it is just possible 

 that M. David may only have met with immature specimens. 

 A trained female, evidently immature, which - the late Mr. 

 Swinhoe obtained at Tientsin t^ and which is now preserved in 

 the Norwich Museum, has the two central rectrices unspotted 

 and unbarred, and is generally in the ordinary plumage of 

 a Saker of the first year, except that the spots on the other 

 rectrices are unusually small, and that the mantle is beginning 

 to show slight traces of transverse bars. Should G. milvipes 

 be really a distinct species (which, as I have already men- 

 tionedj I greatly doubt), this Falcon may prove to be an 

 immature specimen of that race. 



I may add that the most western specimen resembling G. 

 milvipes which has come under my notice is one from Athens, 

 in the Norwich Museum. I have never seen this phase of 

 plumage from any other European locality, except on the 

 Volga, or from Northern or North-eastern Africa ; but this 

 may have arisen from the scarcity of African specimens and 

 of non-Eussian European examples. 



* Vide David & Oustalct's ' Ois. de la Chine,' p. 32. 

 J Vide Ibi?, 18G1, p. 326, and 1803, p. 88. 



