292 MR. H. SAUNDERS ON THE GREY-CAPPED GULLS. [May 5, 



identical— an opinion the value of which is somewhat impaired by 

 the fact of their having confounded one or both of these species 

 with others from which they are most certainly distinct. This has 

 doubtless arisen from the want of a sufficient series in which the 

 localities have been duly recorded ; for specimens of the birds in 

 question, and of those with which they have been confounded, are 

 extremely rare in collections; and it is only recently that I have 

 been able to obtain such a series as would justify my speaking with 

 some confidence on the subject. 



First, as regards the distinctness of the African and the American 

 forms, I have before me the following specimens : — 



LARTJS PH.EOCEPHALUS. 



Senegambia, Swainson's coll., Cambridge Mus. Believed to be 

 the type : ad. 



Walvisch Bay (Andersson), probably in October. Ad. ; full hood. 



Lake Ngami (Chapman, May 1863). Hood slightly imperfect. 



Wing 12-5, tar. 1-8-2, middle toe and nail 1*7, bill 1-4. Colour 

 of legs and bill orange-red. 



Larus cirrhocephalus. 



Buenos Ayres, c?& $ ad., several specimens, those killed in April 

 and November having the grey cap equally defined ; also immature 

 specimens obtained in April, and in which the grey hood is appearing, 

 although the dark bar to the tail and the brown feathers on the 

 shoulders still remain. 



$ . Chorillos, near Lima, lat. 12° 10' S.; the first recorded instance 

 of its occurrence on the Pacific coast. This was shot by a friend 

 resident at Lima, whom I had asked to collect Gulls &c. 



Wing 13-13-5, tar. 2'2-2-4, middle toe and nail 2, bill fr+r 

 Bill legs, and feet lake-red ; in a very old male of the brightest 

 crimson. 



The same description would apply to either : the hood pale grey 

 with a dark margin ; the wings and mantle rather darker than the 

 hood, but much lighter than the under wing-coverts, which are of a 

 deep smoke-grey ; underparts and tail pure white. But it will be 

 observed that there is a considerable difference both in the size and 

 in the coloration of the soft parts of the two species ; and this is 

 much more noticeable on handling the different specimens than can 

 be gathered from any mere description. It must be admitted that 

 Svvainson in his original description states that the bill and feet of 

 the African bird are " deep crimson ;" but, with every allowance for 

 fading, I cannot imagine the colour in those I have examined to 

 have ever been more than "orange-red," very different from the 

 livid red or brilliant lake-colour of the American specimens. Of 

 course I am now alluding to adults only ; but, as regards size, a 

 glance at the coarser and stronger feet even in the immature 

 American birds would enable me to distinguish them from the 

 African form. Without, however, insisting too strongly upon the 

 value of these differences, I consider that the two forms are at least 

 [2] 



