96 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



The Juvenal plumage of Sula nehouxi at first glance resem- 

 bles somewhat that of Sula variegata, but is readily distin- 

 guished from it by the narrow feathers of the neck, as well as 

 by the pale brown of the upper breast. The specimen men- 

 tioned by Messrs. Rothschild and Hartert in their first Gala- 

 pagos paper as "probably not in the first plumage, but in a 

 transitional one,"^ is evidently a bird in juvenal ("first") 

 plumage. In the Academy's series there are a number of 

 specimens passing from the down into this plumage. 



In their second paper these gentlemen seem to have been 

 more seriously misled, for the description they give for the 

 "first" (juvenal) plumage of Sula nehouxi fits the young of 

 Sula variegata and not the young of Sula nehouxi. "These 

 birds in the first plumage differ from the adult ones in having 

 the feathers of the head and neck (which in adult birds are 

 narrow and pointed, giving these parts a streaked white-and- 

 brown appearance) shorter, soft, wide and rounded, and of a 

 uniform deep smoke-brown colour, so that the neck is in a 

 striking contrast to the white breast and abdomen."^ Every 

 point here given fits Sula variegata rather than Sula nehouxi. 

 The young of Sula nehouxi have the upper breast pale brown 

 and "the whole neck smoky brown, with paler tips to the 

 feathers,"^ which are long and narrow. There is not the 

 striking contrast between the neck and the upper breast as in 

 Sula variegata. 



Again, in their second paper, Messrs. Rothschild and Har- 

 tert state that in the "first" plumage of Sula nehouxi "the 

 white interscapular saddle, which is so conspicuous in adult 

 wS". nehouxi, is not developed." In every one of a series of 

 thirteen Academy specimens — some partly in the down, others 

 in full, juvenal plumage — the white interscapular saddle is 

 more or less conspicuous, being even more noticeable than in 

 adults on account of the sharper contrast of colors. The 

 young of Sula variegata lack this saddle. 



In the Academy's series of adults, three have the outer 

 primaries in a pulpy state basally: No. 2543, a male taken 

 at Duncan Island on December 9; No. 2570, a female taken at 

 Duncan on December 14; No. 2579, a female taken at In- 



iNov. Zool., V. 6, pp. 178, 179. 

 Hbid., V. 9, p. 407. 

 Hbid., V. 6, pp. 178, 179. 



