20A. Recent Literature* [April 



as orignally announced, has been modified so as to include all the species 

 known to the author, together with a series of 'Appendices,' fifteen in 

 number, each consisting of a special paper reviewing critically some 

 particular group or species. Regarding this additional matter we quote 

 from the preface (p. vi) : — "Since mv notes on Mr. Sharpe's volume were 

 published in the 'Ibis,' I have seen occasion to modify my views as 

 regards a few species, and have obtained additional information as to 

 some others, and these results I have added to mv present list in the form 

 of footnotes, or, when too lengthy to be so introduced, in the shape of 

 Appendices." 



The work is based ostensibly upon the collection of Diurnal Raptores 

 in the Norwich Museum, and indeed furnishes a list of the specimens 

 contained in that establishment; but it is replete with interesting in- 

 formation derived from other sources, among which the British Museum 

 and United States National Museum figure most prominently. The 

 unequalled richness of the material which Mr. Gurney has had at his 

 command may be appreciated when it is stated that of the 473 species 

 and subspecies given in the catalogue, and embracing all that are known, 

 no less than 385, represented by 2895 specimens, are contained in the 

 Norwich Museum.* 



The 'Appendices' which pertain specially to North American Fal- 

 conidse are the following: 



'Appendix H. On the Genus Butcola.' Pp. 146, 147. 



'Appendix N. On the Existence in North America of Hierofalco 

 gyrfalco, and its possible Hybridism with H. kolbcvlli.' Pp. 161, 164. 



Under the first heading are treated the Buteo brachyurus Vieill., and 

 />'. fuliginosus Scl.,f which are considered to be light and dark (melan- 

 istic) phases of one species. Regarding the Gyrfalcons, Mr. Gurney says : 

 "The result of the comparisons which I have here recorded leads me 

 to agree with the conclusion previously arrived at by Mr. Sharpe and by 

 Mr. Dresser that H. gyrfalco is found in the northern parts, not only of 

 Europe and of Asia, but also of North America. The North American 

 range of this species, however, has not at present been very clearly as- 

 certained, especially to the eastward, and a similar uncertainty exists as 

 to the western limits of //. Iiolbcrlli. as also to the localities, if such there 

 be, where both races occur and where hybridism may perhaps result from 

 such propinquity. As I have already mentioned in my Notes, the Nor- 

 wich Museum possesses three immature Falcons from Hudson's Bay, and 

 these I believe to be referable to H. gyrfalco; but as they are not in adult 

 dress, I do not feel absolutely certain of the correctness of this identifi- 

 cation. The question of the geographical range of these Falcons is one 

 which I think affords an interesting subject for further investigation, and 

 which I trust will receive the attention it merits." 



As to other North American species of the family there are few de- 

 partures from the nomenclature of Bulletin 21 of the United States 



* Of Owls, the same museum possesses 171 species and 1009 specimens! 

 I Cf. Bull. Nutt. Orn. Club, VI, Oct. 1881, pp. 207—214. 



