97 



Larus dominicanus. 



A young specimen sent by Captain Abbot, 



Gavia roseiventris, Gould, sp. nov. 



I describe this Gull as new, with a degree of hesitation, since it is 

 hardly to be supposed that a bird of this magnitude, and doubtless, 

 like the other members of the group, of very wandering habits, should 

 not have been noticed and described. Still I can find no description 

 which answers to this somewhat anomalous bird ; neither does it ac- 

 cord with any of the numerous species contained in our national 

 Museum. I make use of the word anomalous, because, although I 

 cannot separate it from the little group of Gulls, of which our well- 

 known species Gavia ridibunda forms a part, it differs from them in 

 several particulars. In the first place, the specimen, which is cer- 

 tainly fully adult, has a nearly white head, the hinder part only 

 being clouded with dusky, inducing the belief that a black hood was 

 its characteristic at another season ; yet, strange to say, the bill, 

 legs, and feet are of the most intense coral-red ; moreover these 

 organs are very thick and fleshy, much more so than is ever seen in 

 G. ridibunda and its allies ; the gape, also, is wider than in the other 

 members of the group, while the bill and tarsi are shorter ; the 

 hind toes of this, the only specimen I have seen, are well developed, 

 but are entirely destitute of nails (probably from accident or injury) • 

 and, lastly, the neck and breast are suffused with a beautiful pinkish 

 rose-colour — a colour, which, in spite of every care, disappears after a 

 time, and which has sensibly diminished during the two months it 

 has been under my notice ; the three first primaries have their ter- 

 minal portions entirely white, and the tail also is white, in which 

 respects it agrees with the Black-headed Gulls in the British Mu- 

 seum, said to be from the Falkland Islands and the Straits of Ma- 

 gellan. 



The following is an accurate description of this Gull : — 



Tail, head, neck, and all the under surface white, suffused on the 

 breast and abdomen with rich pinkish rose-colour ; back of the head 

 clouded with dusky ; back and wings silvery-grey ; primaries white, 

 the first narrowly edged on the base of the external web, and broadly 

 marked on the base of the internal web, with black, the remainder 

 broadly margined on the internal web with black nearly to the tip ; 

 tail white ; bill, legs, and feet coral-red. 



Total length 13 inches, bill If, wing 1 \ \, tail 3|, tarsi 1J-. 



Ground-colour of the egg light olive, elegantly variegated' with 

 irregularly-shaped markings of umber-brown, disposed in a zone 

 near the larger end, and continued more sparingly over the whole 

 surface, some of them appearing as if beneath the surface of the 

 shell : these markings assume various V-shaped, arrow-headed, tail- 

 shaped, and other fantastic forms. A lengthened and very pretty egg. 

 Length 2 inches ; breadth If. 



No. 390.— Proceedings of the Zoological Society, 



