RARER BRITISH BIRDS. 63 



BROWN-HEADED GULL. 



Chroicocephalus Capistratus. TEMMINCK. 



THE above bird appears to have been first distinguished by 

 Temminck, from Larus Ridibundus, under the name of L. Ca- 

 pistratus. It is one of those species which belong to our new 

 sub genus, having the head white in winter, and brown in sum- 

 mer. It has occurred, according to the last mentioned author, 

 in the Orkneys, Scotland, in Baffin's Bay, and Davis's Straits, 

 and has been shot, according to Mr. Jenyns, in Ireland, by Mr. 

 Thompson. 



Its plumage during winter, according to Temminck, is precise- 

 ly similar to that of L. Ridibundus, but may be distinguished 

 from that Gull by the difference in size, it being smaller ; and 

 by its bill being also smaller and more slender ; it differs also in 

 the measurements, L. Capistratus being fifteen inches in length, 

 and the length of the tarsi being one inch and six lines ; while 

 those of L. Ridibundus are as follows : Length, seventeen 

 inches and a half; length of tarsi, one inch and three-quarters. 



In the summer plumage, the above bird has the head and 

 upper part of the neck of nearly the same colour as in L. Ridi- 

 bundus, dull brown, but is edged below with a ring of darker 

 brown, lowest in front, and not descending below the occiput 

 behind ; scapulars and wing coverts, blueish ash ; quills, white, 

 though tipped and edged with black ; the remainder of both 

 upper and lower plumage, white; bill, legs, and feet, of a 

 reddish brown. The eggs, according to Temminck, are rather 

 smaller than those of L. Ridibundus. Nothing appears to be 

 known regarding its habits. 



