Vol. II, Pt. I] GIFFORD— BIRDS OF THE GALAPAGOS ISLANDS 29 



male, taken May 9 in latitude 2° 20' South, longitude 90° West, 

 is in a somewhat similar condition. 



A male, captured on May 21 at sea south of Duncan Island, 

 is in worn plumage, but with renewals taking place both in 

 the body-plumage and in the flight-feathers. Two males from 

 Indefatigable Island captured in July, are in a like state; but 

 the replacement has progressed farther. 



In all cases the pin-feathers appear black in contrast to the 

 feathers of the disappearing plumage. 



The Academy's series of adults, forty-six males and fifty- 

 three females, gives the dimensions in millimeters of the 

 species as follows: Males— Wing 250-291 (279); tail 136- 

 173 (161); culmen 37.5-43.6 (40.8); tarsus 21.6-25.5 

 (24.2) ; middle toe 27.6-33 (31). Females— Wing 249-280 

 (272) ; tail 131-167 (155) ; culmen 35.5-42.8 (39.3) ; tarsus 

 21-25 (23.4); middle toe 27.3-31.7 (29.8). 



Table IV, p. 113, shows the measurements of adults from 

 the four localities visited. The Galapagos specimens average 

 somewhat smaller in certain respects than their northern 

 relatives. 



Four males from the Galapagos Islands measured in milli- 

 meters in the flesh as follows: Lengths 396, 400, 401, 440; 

 extents 824, 839, 845, 855. Six females from the same lo- 

 cality measured : Lengths 380 , 380, 392, 396, 400, 400 ; 

 extents of five 784, 809, 813, 813, 821. 



The Academy's series of seventy-eight eggs exhibits no 

 noteworthy variation in either coloration or form. It shows 

 the variation in size to be : Length 47.4-56 mm. (51.1 mm.) ; 

 breadth 32.2-38.5 mm. (35.5 mm.), 



Micranous diamesus : Clipperton Noddy 



This species was often seen in company with the Noddy, 

 and in many cases, when the birds were seen at sea, it was 

 impossible to distinguish the species with certainty. 



On August 7, 1905, off Clipperton Island, Mexico, the first 

 Clipperton Noddy was observed, and on the 9th the species 

 was again certainly identified. 



On August 10, Clipperton Island was visited, and this 

 species was found nesting very commonly on Clipperton Rock. 

 The nests, built of algfe from the lagoon, were placed on little 



