Vol. II, Pt. I] GIFFORD— BIRDS OF THE GALAPAGOS ISLANDS 31 



prenuptial moult, or else through the first postnuptial moult. 

 The moult involves the entire plumage in both cases. It is to 

 be noted that, in No. 1525, the two lateral and several of the 

 median rectrices have been renewed, while in No. 1548, the 

 renewal seems to be starting with the median rectrices. The 

 remaining twenty-seven specimens are to all appearances 

 adults in worn nuptial plumage. Nearly all are entering upon 

 the postnuptial moult, as attested by pin-feathers in the back 

 and breast and, in a few cases, by new inner primaries and 

 new rectrices. No. 1523 exhibits a pure white feather at the 

 base of the hind neck ; aside from this, no trace of albinism was 

 noted in the species. 



Twenty-three Cocos Island adults are in a state somewhat 

 similar to that of the Clipperton Island specimens, the breed- 

 ing-season on the latter island evidently being later. In some 

 cases the moult of the body-plumage, particularly anteriorly, 

 seems to be farther advanced. Four immature specimens 

 from Cocos Island, Nos. 1528, 1573, 1591, and 1592, seem to 

 be comparable to Nos. 1525 and 1548 from Clipperton. It is 

 presumed that the moult in this case is the first postnuptial. 

 One specimen, No. 1528, seems to have recently acquired new 

 primaries ; in fact, the distal primary in each wing is just ap- 

 pearing from its sheath. Thirty-four Cocos specimens are in 

 the Juvenal plumage, and give no evidence of postjuvenal 

 moult except an occasional pin-feather in the crown and back 

 of several. September 13 is the latest date on which specimens 

 were taken. 



Certain adults show to some extent the character ascribed 

 by Messrs. Snodgrass and Heller to Micranous hawaiiensis in 

 the following sentence: "In M. hazuaiiensis the pale slaty 

 plumbeous color of the back of the head and neck reaches so 

 far ventrally on the sides of the head and neck, and even on 

 the upper part of the breast, that there is distinctly marked off 

 on the chin and throat a median longitudinal area of dark 

 plumbeous-brown well defined on each side against the paler 

 lateral parts. "^ 



The Academy's series of the Clipperton Noddy numbers 

 ninety-three specimens, twenty-six of which are adult males, 

 and thirty adult females. The adult males average in milli- 



^Proc. Wash. Acad. Sci., v. 4, p. 510. 



