a paper on the collection of birds brought home by the ' Challenger,' contributed by- 

 Mr. P. L. Sclater to the ' Proceedings ' of the Zool, Soc. for 1878, which included a de- 

 scription of this specimen drawn up by myself, and subsequently reprinted in the Official 

 Scientific Report of the Voyage of the ' Challenger,' Zoology, vol. ii. pt. 8, p. 96. This 

 description was in both cases rendered inaccurate by an unfortunate printer's error, 

 owing to which the occiput and hinder part of the neck were misprinted as beinc 

 ' white-coloured ' instead of ' whole-coloured ; ' this error was, however, rendered less 

 important by an accurate coloured figure of the specimen, which formed plate 21 of 

 the ornithological volume of the 'Challenger's' Report. The missing specimen subse- 

 quently came to light, and proved not to be very different in plumage to the female 

 which had been figured, though probably a somewhat younger bird. This specimen 

 was described by me at p. 141 of my ' List of Diurnal Birds of Prey,' published in 1884. 

 "Both the specimens brought home by the ' Challenger' are now preserved in the 

 British Museum. 



" The figure of Buteo solitarius published in the Report of the ' Challenger' Expedi- 

 tion struck Mr. Ridgway as so closely resembling the second example of Onychotes 

 gruheri which had been acquired by the Smithsonian Institution that he was led to a 

 further investigation of the subject, which resulted in his being convinced that these 

 two names had in fact been assigned to one and the same species. 



" Mr. Ridgway published the conclusion at which he arrived, and the data which led 

 to it, in the 'Proceedings' of the United States National Museum for 18S5, p. 36. 



" The Editors of ' The Ibis,' at p. 450 of the volume for 1885, announced and 

 accepted the conclusion at which Mr. Ridgway had arrived, and as to the correctness 

 of which there can, I think, be no possible doubt. 



" Mr. Ridgway, in his paper above referred to, expresses the opinion that ' the genus 

 or subgenus Onychotes .... is tenable ' for the present species, and gives a diagnosis 

 in support of that view ; but my own feeling is that the Hawaiian Buzzard does not 

 differ sufficiently from other members of the genus Buteo to make it needful to refer it 

 to a distinct subgenus. It is of very similar dimensions to Buteo pennsijlvanicus, and 

 their proportions, though different, do not differ very greatly, as may be seen by the 

 annexed comparative measurements (in inches and decimals) of an adult of each of 

 these two species; but I ought to add that I believe the sexes of the specimens 

 measured are different, B. solitarius being probably a male, and B. j^nnsylvanicus a 

 female. 





Culm en 









Middle toe 



Claw of 



Hind toe 



Claw of 



ere. 



without 



Wing. 



Tail. 



Tarsus, 



without 



middle 



without 



hind 





cere. 









claw. 



toe. 



claw. 



toe. 



■30 



•95 



10-75 



6-20 



2-80 



1-70 



•80 



•70 



1-30 



25 



•75 



11-30 



6-40 



2-50 



1-35 



•65 



•70 



1-10 



B. solitarius 



B. pennsylvanieus . . 



" If I am correct in my view as to the normal immature and adult plumages of 

 Buteo solitarius, the following list will enumerate the specimens now existing in 

 different English and American collections so far as I am acquainted with them : — 



