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



and are not those of the juvenal plumage, but are similar to 

 those of adults. The assertion might be ventured that this 

 specimen is assuming the first nuptial plumage. A few worn 

 feathers in the mantle, similar to those of adults, are of no 

 significance, since a few such feathers are common in birds in 

 juvenal plumage. 



Quite a few white-headed young similar to the one de- 

 scribed^ by Mr. Saunders from Paracas Bay, Peru, were seen 

 at sea in May and June, and at Hood Island in February, June, 

 and September. Some have brownish tips to the crown-feathers, 

 but these disappear as the birds grow older, the crown becom- 

 ing pure white. The pale tips of the feathers of the back wear 

 off to some extent with increasing age, giving the upper parts 

 a much duskier appearance. There are gray feathers in the 

 backs of young birds in juvenal plumage, foreshadowing the 

 beautiful mantle of the adult stage. As remarked by Mr. 

 Saunders^ the primaries of the young are like those of the 

 adult in markings, even in the very youngest in which they 

 are developed enough for examination. They seem, how- 

 ever, to be more pointed and less rounded terminally than 

 those of the adult. Five June specimens fom Hood Island 

 are in juvenal plumage, more or less worn, but showing no 

 evidences of moult. The same remarks apply to a male taken 

 on Hood on September 28, 1905. Mr. Beck gives the fol- 

 lowing colors for the naked parts of a young female just 

 fully fledged : Bill blackish ; feet grayish white. 



In a downy young one (No. 1658 C. A. S.) taken on Hood 

 Island on February 6, the scapulars are just appearing, being 

 fawn-color with dark brown bases. The down of the upper 

 parts is brownish gray. Below it is chiefly white, shading to 

 pale gray on the throat and chin. Much of the white down 

 on the anterior part of the body has grayish hair-like tips. 

 On the posterior portion of the body the down seems to be in 

 two sections. The upper section in some cases is gray, and 

 the lower white. The gray grows from the tip of the white, 

 and at the junction of the two the filaments are gathered into 

 a single, slender, compact stem. 



An examination of young Larus occidcntalis at approxi- 

 mately the same age as the downy Creagrus furcatus was 



iCat. Birds Brit. Mus., v. 25, p. 166. 



