REMARKS ON THE GENUS SULA. 311 



throughout enormous intervening- tracts, and I hope some one 

 in Europe will critically examine all the available specimens 

 and see whether this is or is not the case. 



In the meantime Captain Butler's birds and Captain Shelley's 

 are I think identical, but whether they are really melanops 

 of Hartl. is by no means equally clear to me, though a priori 

 I should think they must be. 



The colours of the soft parts and dimensions of Captain 

 Butler's specimens have been above noted. 



Both are in precisely the same plumage, just passing 

 apparently into the so-called adult as distinguished from the 

 old, and are, as I take it, about two years old. 



The moult of the wings has been completed, that of the tail 

 is in progress, that is to say, amongst full-sized, more or less 

 abraded, dull brown feathers are mingled, short, growing, satiny, 

 deep chocolate brown ones. 



In one bird's tail, old and new, I can only discern 12 feathers ; 

 in the other, including four very short ones, there are eight on one 

 side, and six on the other, so that there really probably are 16 

 feathers in the perfect tail. 



The whole of the quills, longest scapulars, winglet, greater 

 and median coverts, and tail, except old feathers, are a rich deep 

 umber brown inclining to chocolate. 



The whole of the rest of the bird may be said to be white, 

 but there is a faint creamy tinge in most of the white feathers 

 of the upper surface, a good many brown feathers are mingled 

 in the median rows of the lesser wing and upper tail-coverts, 

 and some of the median scapulars are brown or brownish grey 

 towards their tips. There are a few brown feathers on the 

 flanks — and a dull pale ferruginous stain (whether natural, or 

 the result of grease acquired in skinning I cannot say,) over 

 the central portion of the abdomen. 



The chin, throat, breast, sides, axillaries, wing lining are pure 

 white, except two or three brown feathers amongst the latter 

 just below the carpal joint. 



The quills are grey or whitish towards their bases on their 

 inner webs. 



In the most perfect tail the central feathers exceed the 

 exterior lateral oues by 2*65. 



The distance measured straight from the tip of the upper 

 mandible to the commencement of the feathers on the throat 

 is exactly 5 inches in both specimens. 



4A. — Sula dactylactra, Less. Voy. Coq. Zooi. I., pt. 

 2, 494, 1826, sine deseu 

 Tr. d'Orn. 601, 831 descr. orig. 



