Birds of Pennsylvania. 3 



on various water plants. They confer no especial benefits, nor are 

 they in any particular detrimental to agricultural interests. Their 

 flesh is seldom eaten ; the feathers, however, are considerably used by 

 milliners, and for the manufacture of muff's, etc. For these purposes 

 the beautiful silvery-white plumage of the breast and abdomen are 

 mostly taken. 



Suborder CEPPHI. Loons, Etc. 

 Family URINATORID^. Loons. 

 Genus URINATOR. Cuvier. 

 7. Urinator imber (Gunn.). 



Ijooii ; Great Northern Diver. 



Desckiptiox. 



Bill compressed, strong and tapering, outline or upper mandible nearly straight, 

 very slightly curved ; the lower mandible has a groove underneath, running from 

 the junction of tlie crura towards the point ; the tail consists of twentj^ feathers. 



Adult. — Tlie liead and neck are darlc bluish-green, the upper part and sides of the 

 head glossed with pvirple ; there is a small transverse mark on the throat, composed 

 of white feathers of a quill-like form, distinct from eacli other, and placed longitu- 

 dinally on each side of the neck ; lower down are larger patches of white, of the same 

 peculiar form, and running in the same direction; these almost meet behind, and in 

 front are about one inch apart ; the effect of these pure white feathers, relieved by 

 tlie dark color of the neck, is very beautiful ; the upper plumage and wing coverts 

 are deep glossy-black, beautifully marked with pure-white spots placed in regular 

 transverse rows, slightly curving downwards: these spots, on the upper part of the 

 back, are small and nearly round, but, as they descend lower on the back, increase 

 in size, and become quadrangular in form, being largest on the sciipularies ; on the 

 lower part of the back, upper tail coverts, and sides (which are black), the spots are 

 small and round ; the sides of the neck, near the shoulder, are beautifully lineated 

 with black and white; the primaries, secondaries, and tail, brownish-black; the 

 under surface glossy-white, with a narrow band of dusky feathers crossing tlie lower 

 part of the abdomen, and marked with small white spots ; lower tail coverts blackish- 

 brown, tipped with white ; bill black ; iris deep bright-red ; tarsi and feet grayish- 

 blue externally, tinged on the inside with pale-yellowish red ; webs brownish-black ; 

 claws black. 



Young. — The plumage above is grayish-black, the feathers of the back margined 

 with grayish-white, the under plumage pure-white ; bill yellowish, with the ridge 

 of the upper mandible dusky ; iris brown. 



Length, 31 inches ; wing, 14 ; tarsus, 3i ; bill, .3 ; height at base, 1 inch. 



Hab. — Northern part of Northern Hemisphere. In North America breeds from 

 the northern tier of States northward ; ranges in winter south to the Gulf of Mexico. 



This bird, the largest of all the Divers, is about as large as a medium- 

 sized domestic goose. Loons are abundant on the Atlantic coast and 

 about the lakes and large rivers in the interior ; oftentimes solitary 

 birds (mostly in immature plumage) are observed, during the winter 

 season, frequenting our smaller streams and mill-ponds. The Loon, 



