Letters, Extracts, Notices, <5fc. 361 



XXXVII. — Letters, Extracts, Notices, ^c. 



ave received the 

 Editors of The Ibis :'— 



We have received the following letters addressed to the 



Sinitlisonian Institution, 

 21st April, 1887. 



SiRs^ — The articles by Canon Tristram on the supposed 

 breeding-plnmage of Fodicejys occideritalis, Lawr., in the 

 January and April numbers of ' The Ibis,' interest me exceed- 

 ingly, inasmuch as it is a great mystery to me what tiie 

 species can be to which he refers. It certainly is not P. oc- 

 cidentaJis, whose breeding-plumage has long been well known 

 to American ornithologists, and is accurately described in 

 the 'Water-Birds of North America^ (vol. ii. p. 422), from 

 numerous specimens obtained on the breeding-grounds, together 

 with their eggs and young. In none of these is there the 

 slightest indication of any ornamental tufts or other dis- 

 tinctive features so characteristic of most (but not of all*) 

 Grebes during the nuptial season. 



The numerous specimens of P. occidentalis in breeding- 

 plumage which I have been able to examine, and which are 

 chiefly in the collection of the United States National Museum, 

 are absolutely similar in all essential characters of plumage to 

 midwinter specimens [and young birds also) , the only apprecia- 

 ble difference consisting in the greater intensity of the blackish 

 colour of the pileum and hind neck. Even the downy young 

 is very different from that of other Grebes, being absolutely 

 destitute of markings of any kind, the upper surface being 

 entirely plain brownish grey (lighter on pileum and hind 

 neck), and the lower parts continuously pure white. It is 

 this '' immutability " of plumage which, scarcely less than 

 marked peculiarities of structure, separates P. occidentalis 

 (and also P. clarkii, Lawr., if this proves valid) from all other 

 known Grebes, not excepting even its supposed near relation 

 P. major (Bodd.), of South America. The latter, though 

 somewhat resembling P. occidentalis superficially, is in all 



* E.g., the species oi Podilymbus, in which, however, there is a black 

 throat-patch, while the bill is coloured very diiTerentlj^ in summer and 

 winter. 



