540 Capt.SAB1NE’s Memoir on the Birds of Greenland, $c. 
Nos. 110, 111 and 112, which he calls Svarbag, Ringvia and 
Alga; the two former Iceland and the latter Danish birds: he is 
undetermined whether these be distinct species, or the present 
in different states of plumage: I am.inclined to consider the 
latter supposition as the correct one. | 
It will be necessary to make some alteration in the specific cha- 
racter of Uria Troile, as given in Gmelin and Latham, to distin- 
guish it from Uria Briinnichi. It is therefore proposed to de- 
scribe the two species as follows: 
U. Troile. U. corpore fusco, pectore abdomineque niveo, remi- 
gibus secundariis apice albis, rostro longitudine capitis : 
mandibula superiore quadruplo longiore quam lata. 
U. Brünnichii. U. corpore fuliginoso, pectore abdomineque ni- 
veo, remigibus secundariis apice albis, rostro capite breviore : 
= mandibula superiore triplo longiore quam lata. 
15 URTA GRYLLE. lack C ullemot 
U. Grylle. Temm. 608. Fabr. 92.—Black Guillemot. Br. Zool. ii. 163. Mont. Dict. & 
Supp. Lath. Syn. vi. 339. & Supp. 265. 
MATURE WINTER. -U.  Grylloides. Brün. mo. 114. —U. ea Brün. 
nos. 115 & 116. | 
MATURE SUMMER. U. Grylle. Brin. no. 113. Lath, Ind. Orn. ii. 197.—Co- 
lymbus Grylle. Gmel. 584. Faun. Suec. 52.—Colymbus Gryllus. Müll. no. 151.— 
» Black Guillemot. Arct. Zool, ii. 516. 
'The states of plumage of this bird are clearly described from 
the extensive and accurate observation of Fabricius. The young, 
when just feathered, are spotted black and white beneath, but 
otherwise resemble the parents. On the approach of winter the 
whole become varied with black and white; the feathers of the 
back margined with white; the head, throat and breast, white 
lightly spotted with black, the'wings continuing black, and the - 
speculum 
