572 ALc^. 



w-y. S $ ad. et Wijde Bay, Spitsbergen, A. Trevor-Battye, 



juv. sk. Aug. 4. " Esq. [P.], 



s. (S ad. sk. Cape Neale, Franz Josef Jacksou-Harnisworth 



Land, July 24 (^F. G. Jack- Exped. [P.]. 



son), 

 a. Skeleton. Greenland. 



b'. Skeleton. Great Britain. Meinertzhagen Coll. 



c', d'. Skeletons. Old Coll. 



4. UEIA. 



Type. 



Uria, Brisson, Orn. tI. p. 70 (1760) U. troile. 



Cepphus, Pallas, Spicil. Zool. fasc. v. p. 33 (1769) U. grylle. 



GryUe, Leach in Huss' Voy. Ex^il. Baffii{s Bay, App. 



p. li (1819) U. mandti. 



Lomvia, Brandt, Bull. Ac. St. Petersh. ii. p. 345 (1837). U. troile. 

 Cataractes, G. R. Gray [_ex Moehriny Av. Gen. p. 68 



(1752)], List Gen. B. p. 98 (1841) U. troile. 



Bill elongate and moderately compressed ; culmen more or less 

 curved downward towards the tip. Inter-ramal feathering extend- 

 ing to or slightly beyond a vertical line drawn from the anterior 

 border of the nasal opening, which is linear and partially or almost 

 entirely concealed by dense feathering extending nearly or quite to 

 the anterior border. Tail composed of 12 or 14 feathers. Meta- 

 tarsus shorter than the middle toe and claw. Size moderate. 



Range. Arctic Ocean, Bering Sea, and the northern parts of the 

 Atlantic and Pacific Oceans. 



Keii to the Species. 



I. Tail composed of 12 feathers ; lining of wing white. 



A. Wing-coverts uniform greyish black ; tips of 



secondaries white. Size larger, wing 7'5-9"l 

 inches. 



a. BiU more slender and elongate ; the feathering 



on the basal part of the upper mandible 

 extending to the cutting-edge. 

 «'. Feathers roimd the ej'e and along the crease 



behind it black troile, p. 573. 



b'. Feathers round the eye and along the crease 



behind it white rinyvia, p. 575. 



b. Bill stouter ; basal part of the upper mandible 



not covered with feathers lomvia, p. 577. 



B. Greater and median wing-coverts forming a large 



white patch on the wing ; secondaries not tipped 

 with white. Size smaller, wing 6-6"4 inches. 



c. Basal half of the primary-coverts black yylle, p. 580. 



d. Primary-coverts white almost to the base .... inandti, p. 584. 



II. Tail composed of 14 feathers ; lining of wing grey. 



C. A large double white patch on the wing, iormed 



by the median and the tips of the greater wing- 

 coverts colwnba, p. 586. 



