NOVITATES ZOOLOGICAE XXII. 1915. 183 



Falco rusticolus candicans : Greealand and Arctic America. 

 Falco rusticolus obsoletus : Labrador. 

 Falco rusticolus uralciisis : North Siberia. 



I am afraid some lengthy explanations are nece.ssary — tlioagh partially given 

 in Viiig. pal. Fauna, ii. pp. 1064-1009 — to justify my view, and I shall compare it 

 with three other recent attempts to separate these Falcons into species and sub- 

 species : each different from mine as well as from each other ! 



First with regard to nomenclature : 



In the most important point of this I agree, as usual, with the A. 0. U. Check- 

 list, as far as priority is concerned. I also accept the name rusticolus, which is the 

 oldest of all, dated from Linnaeus, 1758. Though its diagnosis in the Sijst. Nat. 

 Ed. X. i. p. 88, is very meagre, the fuller description in Fauna Suecica, 2nd ed., 1761, 

 enables us to understand, in my opinion, what Linnaeus meant with his rusticolus. 

 It is therefore advisable, because it simplifies matters, to accept the name rather 

 than let it stand with a query and threatening to be taken up afterwards by any 

 purifier of nomenclature. Thns Falco gijrfalco becomes a synonym of rusticolus. 



The Greenland bird can only be called candicans, and in this we all agree. The 

 Iceland bird is, by general consent, called islandus, though Briinnich united the 

 Iceland and Greenland Falcons. 



American ornithologists {A. 0. U. Check-list, 1910, p. 163) allow to occur 

 in North America : 



1. Falco islandus. 



2. Falco rusticolus rusticolus. 



3. Falco rusticolus (jijrfalco. 



4. Falco rusticolus obsoletus. 



This is obviously wrong. First of all they seem not to have grasped the fact that 

 the Ifortherii Falcous vary individually like Buzzards. They evidently distinguish 

 their four forms by some colour-differences ; but how such closely allied forms as the 

 F. islandus and the Gyrfalcous can be more than subspecies, I do not understand, 

 and less, how two birds described from Sweden can be two different subspecies, 

 both breeding in North America. 



Mr. Ogilvie-Grant has shown me at least one evidently adult dark Falcon from 

 Labrador, which has convinced me that there is such a form as " obsoletus " ; this 

 is most fortunate, as otherwise, if it were based on dark young candicans, the name 

 obsoletus, being older than candicans, would have to be nsed for the Greenland 

 Falcon ! 



With regard to the American islandus, it is the Greenland form, our candicans, 

 ■while their F. rusticolus rusticolus and gi/rfako are merely colour-variations of 

 candicans. Should a bird occur in North America which is indistinguishable from 

 the Scandinavian form, it would by me be regarded as either a stray bird, or 

 as a proof of the correctness of my view, that all Northern Falcons are but 

 subspecies, because sometimes indistinguishable. 



In the Hand-list of Birds, vol. i. p. 276, Sharpe distinguished between : 



\. Hierofalco* candicans: Arctic Regions, Greenland, N.E. America, 



W. Europe (occasional). 

 2. Hierofalco islandus : Iceland. 



• An unnecessary burden ! Moreover wrongly limited, because all the Lanner group belong lo the 

 same section, having absolutely the same structure of the feet and otherwise. 



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