Mr. R. B. Sharpe's Catalogue of Accipitres. 591 



peculiarity of the inner web of one of the central rectrices 

 being throughout mottled with two shades of grey instead of 

 the usual transverse barring, which is quite regular and nor- 

 mal on all other portions of the tail. 



Some of the specimens of H. islandus and of H. holbcelli 

 which I have examined lead me to believe that in both these 

 races the pale transverse bars on the mantle are in most in- 

 dividuals less amply developed as the result of the first moult 

 than is the case in subsequent years; and until these bars 

 have been fully developed^ the slight difference which exists 

 between H. islandus and H. holbcelli is, of course, not appa- 

 rent. This remark applies to a Grey Falcon from Labrador, 

 just attaining its adult dress, which Mr. Dresser has been so 

 good as to lend me. This specimen, which appears to be a 

 male, measures as follows : — Wing 14'30, tarsus 2'2Q, middle 

 toe {s.u.) 1-90. 



I may now briefly refer to the remaining member of the 

 subgenus Hierofalco [H. candicans), a species in which indi- 

 viduals of the same age vary much more widely in the dis- 

 tribution and character of their markings than is the case 

 with any other species of this subgenus — so much so, indeed, 

 that it has been well observed by Professor Newton, in his 

 edition of Yarrell's 'British Birds/ vol. i. p. 45, that " a very 

 large series of examples may be compared without finding two 

 ■ohich are exactly similar.^' 



Professor Newton, in a pajjer inserted in the 4th series of 

 the ' Annals and Magazine of Natural History/ vol. xii. 

 p. 485, and Mr. Dresser, in his article upon H. candicans in 

 the ' Bii'ds of Europe,' vol. vi. p. 22, have recorded their 

 dissent from the views propounded in Mr. Sharpens Catalogue 

 as to the sequence of changes incident to progressive age in 

 this species ; and in this dissent I concur. 



As a slight contribution to the facts which have been ob- 

 served bearing upon this subject, I may mention that in the 

 year 1859 the Zoological Society became possessed of a living 

 specimen of H. candicans in what I believe to have been its 

 first year's plumage. In the course of that year Mr. Wolf 

 was so good as to make for me an accurate coloured drawing 



