BLACK-FOOTED ALBATROSS. 329 



fore part of the head, cheeks and throat light dusky-grey, the capis- 

 tral feathers nearly white, as is a small patch at the posterior angle 

 of the eye ; the upper part of the head, the hind neck, and all the up- 

 per parts, including the wings and tail, are of a sooty brown tinged with 

 grey, as are the lower surface of the wings and the axillaries. The 

 lower parts are of a dull grey tint, deeper on the fore parts and sides 

 of the neck. 



Length to end of tail 36 inches ; bill along the ridge 5, along the 

 edge of lower mandible 5 ; wing from flexure 21 ; tail 3 ; bare part of 

 tibia l]j ; tarsus 3ii; inner toe 1^§, its claw ^^ ; middle toe 4.^%, its 

 claw /j ; outer toe 4:^^^, its claw /g. 



The three Albatrosses described in this volume may very easily be 

 distinguished by the form of the bill, independently of all other cha- 

 racters. Thus : 



Diomedea nigripes has the bill much thicker, or less compressed than 

 the other two species ; its ridge very broad and convex at the base, its 

 basal outline being semicircular and two inches in extent, so that its 

 sides behind overlap and obliterate the sutural space behind the nostrils. 



Diomedea chlororhynchos has the bill much compressed, its ridge con- 

 vex in its whole length, but with its basal outline, although semicircu- 

 lar, only half an inch in extent, so that between its margins and those 

 of the sides of the bill there is behind the eye a space nearly a quarter 

 of an inch in breadth. 



Diomedea fusca has the bill as much compressed as that of D. chlo- 

 rorhynchus ; but its ridge, in place of being convex, is carinate, and in- 

 stead of having its base semicircular, as in the other two species, has 

 it running up on the forehead into a very acute angle. 



Many other differences might be pointed out, but these will suffice 

 to distinguish the species. It may be remarked, that such descriptions 

 are absolutely necessary to render the species of this genus intelligible ; 

 for at present it seems impossible to form any correct idea from the 

 notices given in books ; and if descriptions are not sufficient to enable 

 one to refer an object to its species, of what use can they be .'* 



