1895.] — ON A MELANISTIC PHASE OF URIA GRYLLE. 8 


Ad 1. As stated above, the type-specimen of U. motzfeldi 
cannot with certainty be pointed out; it is possible that it is 
one of the 3 specimens, viz.: that at Leyden. Whether this be 
So or not, its description seems to me to agree in so great å 
measure with the existing specimens, that it is probable that 
they are all identical. 
Ad 2. U. motefeldi must, in my opinion, be considered as 
a melanistic variety of U. grylle." 
This seems evident from the want of uniformity in the dis- 
tribution of the black colour, no two of the specimens in ques- 
tion being exactly similar. 
It is moreover not very probable that å normal species in 
such carefully examined waters as the KFuropean-Arctic sea 
would be able to keep itself in unchanged, particularly small 
numbers for centuries, when the species, from its nature, must 
be considered as å sub-arctic and essentially littoral, and probably 
stationary form.*) 
Lastly, the fact that both the species allied to Uria grylle 
(viz. U. mandt and U. columba), change tbeir black summer 
dress in the autumn for å much lighter winter dress, deserves 
1) It should here be remarked that Mr. Kumlien (Bull. U. S. Nat. Mus. 
No. 15) in 1877—1878 obtained a black specimen of a Uria at 
Cumberland (Davis Straits). Although U. grylle is known as å spo- 
radic brooder on the coasts of Greenland, and also, according to 
Stejneger, probably in a few localities on the east coast of North- 
America (a specimen in summer dress from Fastport, Maine, is pre- 
served in the Smithson. Inst.), it is possible that the specimen acquired 
by Mr. Kumlien, which was afterwards lost without being minutely 
examined, was a correspondingly abnormal phase of U. mandtii. He 
himself, however, considered it to be ,a melanistic specimen of U. 
grylle*. 
?) Ås previously mentioned, the observer who met with the specimen at 
Christiansund, believed he saw certain features in its habits, in which 
it differed from the other Uria grylle, in whose company it was 
found. This, however, can scarcely be regarded as of essential im- 
portance. If, by reason, perhaps, of its different colour, the bird had 
only a few times been exposed to persecution, it would soon learn 
to keep at a distance; and there is, a priori, little likelihood that å 
form which exteriorly agrees in all other respects (with the excep- 
tion of colour), so exactly with U. grylle, should really have peculiar- 
ities in its habits, different from that species. 
