510 CETOSPARACTES EBURNEUS 



and rough, as in the Petrels. The claws are moderately long, 

 stout, arched, rather acute. 



The plumage in general is full, close, clastic, very soft, 

 and blended ; on the back and Avings compact ; the feathers 

 are elliptical, incurved ; the down copious. The quills and 

 tail-feathers have a slight silky gloss, more conspicuous on 

 their lower surface. The wings are very long, extending 

 about an inch beyond the tail, rather broad, acute ; the outer 

 primaries broad and tapering, the first longest, the second 

 two-twelfths of an inch shorter, both with a slight sinus on 

 their inner web near the end, the rest rapidly decreasing, the 

 secondaries twenty, broad, and rounded, the inner narrower, 

 but rounded. The tail is of moderate length, the outer fea- 

 thers a quarter of an inch shorter. 



The bill is greenish-grey as far as the anterior extremity 

 of the nostrils, then of a rich yellow, tinged with red, the 

 edges horn-colour. The margins of the eyelids vermilion, 

 " the iris brown." The feet and claws are black. The 

 plumage is entirely white, with a slight yellowish tinge ; so 

 that the name ehurncus is more correct than candidus. 



Length to end of tail 20 inches ; extent of wing about 42 ; 

 "wing from flexure 14;} ; tail Q>\ ; bill along the ridge 1-^^ ; 

 along the edge of lower mandible 2\ ; tarsus l-j^V ; hind toe 

 -fj, its claw -fry ; second toe W, its claw -j^ ; third toe 1 -j^^, its 

 claw jV ; fourth toe 1 jV? its claw jV, 



Female in Summer. — In all respects similar to the male, 

 but somewhat smaller. 



Length to end of tail 18 inches ; Aving from flexure 13| ; 

 tail 6 ; bill along the ridge IjV ; tarsus \h ', middle toe IjV, 

 its claw- yV- 



Variations. — Considerable differences as to size are ob- 

 served, but otherwise all the adult individuals that I have 

 seen are similar. 



Habits. — This bird inhabits the arctic regions of both 

 continents, and in particular the coasts of Spitzbergen and 

 Cheeidand, on the cliffs of which it breeds. Accordinc; to 



