3 
14 R. COLLETT. ON A MEL. PHASE OF U. GRYLLE. [No.1. 1895.] 

prominence. "This has not been the case with the black specimen 
from Norway. | 
That Uria grylle more than the other North Atlantic auks, 
should have å propensity for forming melanisms, is perhaps more- 
diffieult to explain. 
It might with equal justice be asked why Stercorarius crepi- 
datus is so often found with å melanistic phase, that in certain 
districts, it almost supersedes the chief form, while such å phase 
is unknown in its near relation, Si. parasiticus (= St. buffoni), 
besides other examples. 
Christiania, 21st Jan. 1895. 


(Printed 14th March 1895.) 
