
12 R. COLLETT. [No. 1. | 
In the Leyden specimen, this light-coloured region is not 
present. ,The whole plumage including the under wing-coverts 
and the base of the inner web of the quills, uniform sooty black, 
faintly glossed with oily green*. (Bittikofer). The London 
specimen, on the other hand, is like the Norwegian in this re- 
spect; ,the basal half (about) of the inner web of the primary 
quills and their coverts (both upper and under) whitish; åa few 
feathers on the crown, mantle and breast are. fringed with 
- whitish buff*. (0. Grant). 
It appears from this, that no constant colour in these black 
specimens is to be found. No one of the three is exactly like 
either of the other two. The Leyden specimen is the darkest, 
the light colour at the base of the wing-feathers being absent; 
the London specimen is the lightest, as besides these lighter 
wing-feathers there are light-coloured feathers here and there 
in other parts of the body. 
No great importance can be attached to the colour of the 
tarsus, as it is not specified in other fresh specimens than the 
Norwegian. The colour of the claws in the specimen at Leyden 
is stated to be ,more horny brown than pure black*; in the 
London specimen, they were ,reddish brown towards the base, 
and black at the tips". This too is a distribution of colour, 
whereby the specimens appear to be mutually diverse. 

The two following questions now present themselves for reply: 
1. Is that form of Uria characterised by its uniformly brown- 
ish black colour (without white wing-patch, and without white 
markings on the head) and of which there are at present 3 
specimens (all from the Greenland or the European-Arctic area) . 
preserved in museums in Europe, the same as that which was 
described in 1824 under the name of Uria Motzfeldi, Ben. (= U. 
unicolor, Fab.)? 
2. May this or these forms be looked upon as distinct spe- 
cies, different from other known species of this group? 
