CATALOGUE OF VERTEBRATES. 625 



Sub-Order LONGIPENNES. 



General characters — Feet palmate ; hind toe small and elevated ; bill 

 long ; wings long and pointed. 



Family STERCORARIID^. 



Skuas and Jaegers. 



STERCORARIUS, Briss. 



8. pomarinus, Temm. (pomatorhinus.) Pomarine Jaeger. 



Covering of upper mandible in three distinct pieces (a terminal 

 hook, and basal cere of separate pieces) ; middle tail feathers 

 project and are broad at ends ; plumage in two phases ; light 

 phase, upper parts sooty ; lower parts and front of head and 

 neck white ; dark phase, no white. Both phases grade into each 

 other. Length, 20 inches; wings, 15 inches. 



" When, as is the case during one winter in every ten, coast 

 birds are unusually numerous, this among others may sometimes, 

 but very rarely, be met with in midwinter." 



S. parasiticus, L. Parasitic Jaeger. Arctic Jaeger. 



General color dark brown, with two extremes as above ; middle 

 tail feathers pointed, project ftur inches. Length, 18 inches; 

 wings, 13 inches. 



" This species is little less abundant than the preceding, and 

 like it, only met with during the winter." 



S. longicaudus, Vieill. Long-tailed Jaeger. 



With middle tail feathers projecting eight or ten inches ; prob- 

 ably gets as far south as New Jersey, in winter, extremely 

 rarely, although a very cold season favors an extension of its 

 migration. 



