312 REMARKS ON THE GENUS SULA. 



nigrodactyla, Less. Bp. Cousp. II. 165, 1850. 



This species, if really distinct, concerns us little. It was 

 procured at Ascension Island, and is not likely, even if distinct, 

 to occur within our limits. 



Lesson's original description is as follows : — ■ 



" Plumage pure white ; wings and tail black ; tarsi yellow ; 

 the base of bill encircled by a naked skin, which extends on 

 to the throat in the shape of an half circle." 



Of course, this may be any thing ; but as according to Bona- 

 parte the original specimens existed in the Paris museum in 

 1850, it is difficult to understand how the matter of their iden- 

 tity or distinctness still remains doubtful. Bonaparte, with speci- 

 mens of both this and cyanops (or at any of per sonata) before 

 him, said they were distinct. 



No writer who unites this species with cyanops, with a ? 

 seems to have examined the types. 



If really identical with cyanops, Lesson's name has of course 

 priority. 



5.— Sula piscatrix, Lin. S. N. I. 217, 1766. 



Candida, Briss. On. VI, 501, 1760. 



erythrorhyncha, Less. Tr. d'Orn. 601, 1831. 



rubripes, Gould, P. Z. S. 1837, 156. 



rubripeda, Peale, U. S. Expl. Expn. Birds, 274, pi. 83, 

 1st Ed., 1848. 

 To these synonymes Tschudi's variegata, of which more here- 

 after is commonly added. 



Brisson's original description is full and excellent : — " It is a 

 little larger than the first species of this genus (sula of Lin). 

 Length from tip of bill to tip of tail 33*96,* and to tip of 

 claws, 27*8; bill from gape, 55 ; tail, 1095 ; foot (tarsus?), 

 1*93 ; mid toe and claw, 3 - 58 ; outer, 2-11 ; inner, 2'1 ; hind toe, 

 1*3; mid toe claw serrated interiorily ; expanse, 67-87 inches. 

 The wings when closed reach to about three-fourths of the 

 length of the tail. 



" The head, neck, body, scapulars, upper and under wing, and 

 tail coverts are white, excepting the upper greater wing coverts, 

 most distant from the body, which are brown. The great fea- 

 thers of the wing are of this latter colour, the medium ones 

 white. The tail of 14 feathers similarly white. The central 

 ones longest, the laterals diminishing as they recede from the 

 centre, so that the outermost on each side is 6'12 shorter than 

 the central ones. The space on each side between the eye and 

 bill is naked and red. The bill, the legs, and toes and their 



* Of course, in this and all other eases I have, in translating, converted French inches, 

 millimetres, &c, into English inches and decimals, 



