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



We landed on Clipperton Island, Mexico, on August 10. I 

 worked about Clipperton Rock, where Noddies were nesting 

 commonly, and were as unafraid as on Oneal Rock. Messrs. 

 Beck and Hunter, who landed on some of the islets in the 

 lagoon, stated that both this species and the Sooty Tern were 

 nesting abundantly, and they obtained eggs and young of both. 



Between Clipperton Island and Cocos Island, Costa Rica, 

 the first certainly identified Noddies were seen on September 

 1, about thirty miles south of Cocos. An immature one was 

 taken on the following day. 



During our thirteen-day stay at Cocos Island, the Noddy 

 was common along our rout-e of travel by water between Chat- 

 ham Bay and Wafer Bay. There was usually a good-sized 

 flock on the point opposite Nuez Island, and also a colony on 

 the small island between Nuez and Cascara islands. A small 

 nesting colony was located on a rock near Conic Island. Their 

 nests consisted of a few twigs, and were occupied by young 

 birds which, with one exception, were nearly able to fly. 



The Academy's series of skins of this species numbers 132. 

 A downy young one from Clipperton Island is entirely white, 

 save for a few black contour feathers appearing on the back, 

 crown, and sides of the breast. The black feathers are tipped 

 with white down. The only specimen in the down from the 

 Galapagos Islands is of a brownish-gray color all over, shad- 

 ing into a paler gray on the abdomen, in contradistinction to 

 the downy young one from Clipperton Island. This fact 

 probably has no geographic significance, for young in both 

 white and black natal down are found in the same colony.^ 



Two young from Oneal Rock are fairly well feathered ex- 

 cept for the throats, which are covered with white downy 

 teleoptiles. In one specimen the contour feathers appearing 

 in the throat are tipped with grayish downy neossoptiles, and 

 in the other with white. All of the young from Cocos Island 

 are pretty well feathered, but show both white and gray down 

 at the tips of the feathers, while the downy teleoptiles are pale 

 gray in most cases. 



Four specimens, Nos. 1439, 1473, 1475, and 1501, taken at 

 Tagus Cove on April 5 and 7, were at that time going through 



^Watson, Papers Tortugas Lab. Carnegie Inst. Wash., v. 2. p. 237, footnote, plate 

 4 (Watson). 



