PROCELARIIDJE. 55 



parts, forehead, tips of longer 

 scapulars and of tail white; wing 



about 8.00...; Halobcena. 1 



z 2 . Depth of bill at shallowest part decidedly 

 less than one-fourth the length of the 

 lower mandible, measured along its side ; 

 plumage bluish gray above, becoming 

 white on forehead and blackish on wings ; 

 beneath entirely white; wing about 



9.00 Cookilaria* 



g*. Partition between nostrils very thick (as wide as or 

 wider than nostril), ending anteriorly "flush" 

 with, or but little behind, the anterior rim of the 

 nasal tubes. 



A 1 . Space between nasal tubes and base of unguis not 

 greater than length of the latter ; nostrils not 

 visible from above ; color uniform sooty black 

 (browner below), with or without white mark- 

 ings on head ; wing 13.50 or more.. Majaqueus? 

 A 2 . Space between nasal tubes and base of unguis 

 decidedly greater than length of the latter; 

 nostrils partly (usually entirely) visible from 

 above ; color and size very variable, but wing 

 never more than 15.00 (usually much less). 



Puffinus. (Page 58.) 

 / 2 . Bill flattened, broader than deep at base. 



Branches of lower mandible bowed widely apart, the 

 space between mostly unfeathered ; plumage spotted 

 white and dusky above, entirely white beneath. 



Daption. (Page 69.) 



e 1 . Inner side of edge of upper mandible with distinct fringe-like 

 processes ; color bluish above, the tail tipped with black- 

 ish ; beneath white ; wing about 7.00-7.50. 

 f l . Culmen concave ; lateral outlines of bill straight. 



Pseudoprion.* 



/ 2 . Culmen straight ; lateral outlines of bill decidedly convex. 



Prion. 6 



d?. Culmen less than half as long as middle toe, with claw; tail 

 even ; hind claw very large, equal in length to the nasal tubes, 

 measured along the top ; color entirely pure white... Pagodroma* 



1 Halobtena " Is. GEOFFR. 1836," BONAP. Consp. ii. 1857, 193. Type, Procellaria cserwlea GMEL. 



2 Cookilaria BONAP., Compt. Rend, xliii. 1856, 994. Type, Procellaria cookii GRAT. 



3 Majaqueus REICH., Av. Syst. 1852, p. iv. Type, Procellaria mquinoctialis LINN. 

 * Pseudoprion COUES, Pr. Ac. Nat. Sci. Phil. 1866, 164. Type, Prion turtur GOULD. 



6 Prion LACEPEDE, Mem. de 1'Inst. 1800-1801, 514. Type, Procellaria vittata GMEL. 

 6 Pagodroma BONAP., Consp. ii. 1856, 192. Type, Procellaria nivea GMEL. 



