TOWNSEND AND WETMORE: THE BIRDS. 171 



5. Fregata ARIEL ARIEL (G. R. Gray). 



Atagen ariel Gray, Gen. birds, 1845, 3, plate 183. (Raine Island, North 

 Australia). 



One specimen, a male, was taken at Makemo, Paumotu Islands, 

 25 October, 1899. The culmen measures 86.5 mm. and the wing 

 495 mm. The gular pouch is not at all developed. There are so few 

 specimens of this frigate-bird available that it is difficult to make out 

 the forms into which it may properly be di^dded. The bird in hand 

 is referred to the typical form. 



ARDEIDAE. 

 6. Demigretta sacra sacra (Gmelin). 



Ardea sacra Gmelin, Syst. nat., 1789, 1, pt. 2, p. 640. (Tahiti). 



Seven specimens were collected in the Paumotu Islands, the Gilbert 

 Islands, and Kusaie in the Eastern Carolines. Two males from 

 Makemo in the Paumotu Islands, were collected, 20 and 23 October, 

 1899, respectively. One is in fine dark plumage, while the other is 

 white save for the elongate dorsal plumes. Of two birds collected at 

 Rangiroa on 21 September, one sexed questionably as a female is also 

 white with dark markings on the longer feathers of the back, while the 

 other (a female) has the crown, sides of neck, breast, wings, and tail 

 pied with dark markings, with white as the predominant color. Two 

 males were taken at Tarawa, Gilbert Islands, 3 January, 1900; one 

 is entirely white, while the other is pied as described in one bird from 

 Rangiroa. A male from Kusaie," collected 8 February, 1900, has one 

 dark feather among the right scapulars, but is white elsewhere. This 

 specimen and the white bird from Tarawa are remarkable in having 

 the elongate dorsal plumes white. 



The status of the white and dark birds is somewhat uncertain, some 

 ornithologists considering them to be distinct species. As dichro- 

 matism is so well known among other herons it is only reasonable to 

 suppose, however, that these birds represent a similar case in the reef- 

 herons. There are evident no structural characters by which light 

 and dark birds may be separated, and color in this instance must be 



