362 Synopsis of the Birds 



ash j tarsus three inches ; tail reaching two inches beyond 

 the wings. 



Summer plumage, head and neck pure white : winter, head 

 and neck with brown streaks. 



Young dingy, mottled. 



Glaucous Gull, Lath. Naum. Vog. pi. 35. 



Inhabits the Arctic regions of both continents : exceeding- 

 ly rare in the United States. 



303. Larus marinus, L. Back and wings slate-black; quills 

 black at the point, tipped with white ; shafts black; wings 

 not reaching beyond the tail ; tarsus three inches. 



Summer plumage, head and neck pure white : winter, head 

 and neck with brownish streaks. 



Young dingy, mottled. 



Black-backed Gully Lath. Wilson's list. Bvff.pl. enl. '990. 

 and 206. young. 



Inhabits both continents : not uncommon during winter 

 in the middle states. 



B. 



Bill of several pieces. Nostrils immarginate. Feet 4-toed. 



Longipennes, 111. Pclagii, Vieill. Ranz. Lari, Boie. 



66. LESTRIS. 



Larus , L. Gm. Lath. Buphaga, Moehring. Catharracta, 

 Brunn. Stercorarius, Briss. Vieill. Lestris, III. Cuv. Temrn. 

 Labbes, Buff. 



Bill moderate, robust, hard, cylindrical, compressed, 

 hooked at tip, edges sharp ; upper mandible with the ridge 

 and tip distinct, covered beyond the nostrils by a cere ; lower 

 of one piece, shorter, angular beneath, obtuse at tip : nostrils 

 subterrainal, lateral, oblique, linear, wider before, pervious, 



