Adult Dress of the Labrador Falcon. 243 



made to them. In the year 1884 one of us (Menzbier). 

 when in London, was fortunate enough, through the kindness 

 of Mr. Dresser, to be able to examine and describe two 

 specimens of the Labrador Jcrfalcon in the collection of 

 that ornithologist. As neither of them shewed any traces 

 of moult, it was impossible to arrive at a decided conclusion 

 as to their age. Notwithstanding this, our study of the 

 Palaearctic as well as of the Nearctic Jerfalcons made us 

 consider the existence in the genus Hierofalco of a species 

 with plumage and legs as described by Mr. Dresser {i.e., 

 almost without any well-marked change of colour depending 

 on age and with blue legs) very singular. 



For the elucidation of this question, when Sushkin was 

 departing for Western Europe, he was requested to visit all 

 the museums where skins of Labrador Jerfalcons might be 

 expected to be found. The Museum of Brunswick (Tech- 

 nischc Hochschule) seemed likely to be of the greatest 

 interest in this respect, and it did not fail to realize our 

 expectations. Through the kindness of Dr. Blasius, Jr., 

 Mr. Sushkin bad the opportunity of examining the whole 

 collection of the late Dr. W. Blasius, and many of the 

 skins were even sent to Moscow for Menzbier to study. 

 We found at Brunswick nine specimens of the Labrador 

 Jerfalcon, more or less agreeing with the description by 

 Mr. Dresser, and three of these were in moult, new feathers 

 being detected on the rump, thighs, and tail. Besides this, 

 traces of moult on the rump and small scapulars were found 

 in one of three specimens in the Museum of Berlin. 



Basing our opinion upon careful examination of moulting 

 specimens, we came to the conclusion that the plumage of the 

 Labrador Jerfalcon which follows its uniform dark brown 

 dress might be roughly characterized as the same as that of the 

 majority of the Jerfalcons, i. e., dark above, with lighter trans- 

 verse markings and a distinct wash of bluish on the mantle. 

 According to these two dresses (first dark brown and secondly 

 transversely marked), the Labrador Jerfalcon would be the 

 nearest relative of the Norwegian Jerfalcon, from which it 

 may be distinguished by the following characters : — The 



R 2 



