496 MR. SCLATER ON THE YELLOW-BILLED CUCKOO. [Mar. 19, 



is the third which has reached Europe alive. The only appearance 

 of horns that our animal possesses consists of two small protuberances 

 just elevated above the skin. Except in the absence of these ap- 

 pendages, it exactly resembles the male of the species. 



Mr. R. B. Sharpe, F.Z.S., exhibited some specimens of Blue Rock- 

 Thrushes {Petrocossyphus). Referring to an article in the tenth part 

 of the * Birds of Europe ' for full details and proofs of the conclusions 

 at which he had arrived, Mr. Sharpe pointed out that the female of 

 the Blue Rock-Thrush of Europe did not always remain in a spotted 

 plumage, as was stated by authors, but ultimately got blue like the 

 male, though she took a much longer time than the latter in assuming 

 the mature livery. In the same way, P. solitarius of China ultimately 

 passed from the blue-and-red stage (P. manilla of authors) iuto a 

 fully blue plumage, in which state it was only distinguishable from 

 P. cyanus of Europe by its smaller size. It was shown that the 

 change from a spotted plumage to the blue-and-red dress was very 

 gradual, as was also the gradation from the blue-and-red plumage to 

 the full blue garb of the adult. P. affinis of Blyth was stated to be 

 nothing but the intermediate stage of the last gradation, and that the 

 variation in this supposed species was caused by the more or less ad- 

 vanced character of the plumage. Mr. Sharpe exhibited specimens 

 (chiefly from the collection of Mr. Swinhoe), tracing all the stages 

 through which the species passes, from the spotted nestling to the 

 fully mature blue bird. 



Mr. Sclater exhibited a skin of the Yellow-billed Cuckoo of the 

 U. S. of America {Coccyzus americanus), which had been shot by Mr. 

 W. H. Hudson, C.M.Z.S., at Quilines, Buenos Ayres, April 21, 1870, 

 and was stated by that gentleman to be the only specimen of this 

 species he had ever obtained. Except in its slightly larger dimen- 

 sions, Mr. Hudson's bird did not differ from other examples of this 

 widely wandering species, of which Mr. Sclater exhibited specimens 

 from Jamaica, Mexico, and the U. S. of Columbia. Mr. Sclater re- 

 marked that there could be little doubt that the bird obtained by 

 Natterer in S. Paulo, Brazil, and referred by v. Pelzelu to Coccyzus 

 bairdi*, was also an accidental visitor of this species, which had so 

 often strayed even into Europe. 



Major Godwin-Austen, F.Z.S., exhibited a skin of Ceriornis bly- 

 thii, and called attention to the differences between this species and 

 C. satyra, C, melanocephalus, and C. cuboti. Ceriornis blythii had 

 been first obtained in Upper Assam by Dr. Jerdon, having been 

 brought from the neighbouring hills. Its exact locality and range to 

 the west, however, were doubtful. The specimen exhibited had been 

 shot by Mr. Roberts, of the Topographical Survey, in the Naga Hills, 



* Orn. Brasil. p. 274. 



