90 



F. Finn — On specimens of two Mauritian Birds, [No. 2, 



Except for this bill and for the sliglitly shorter white lips to the 

 quills, 1736 A is true P. lepturus, which, from the British Museum 

 Catalogue list of specimens, occurs at Mauritius, and it may therefore, 

 I think, be referred to that species, although not entirely agreeing there- 

 with. 



The other specimen, B, however, is not so nearly in agreement with 

 P. americanus, for while it has a nearly completely yellow bill, the 

 white tips of the first four primaries are never so little as half an inch 

 long, and the third quill is not nearly all bla ck, but marked like the 

 rest, although the fifth has a good deal of black along the outer web 

 as in P. americanus. 



Thus these two specimens do not agree with the description of any 

 species of Phaethon; and yet they differ far too much from each other 

 to be referred to a separate form. I am therefore disposed to think 

 that they are both Phaethon lepturus ; and this must be a variable 

 species, since it can produce, in the Old World, one individual showing 

 a considerable approximation to the American P. americanus^ in the 



