30 PROCEEDINGS OP THE NATIONAL. MUSEUM. vol.64. 



While the United States National Museum contains quite a series 

 of these herons, mostly from the northern part of the range of the 

 species, it is j^et inadequate for the working out of the various forms 

 and I am referring the Celebes birds for the present to the typi- 

 cal form, as Wetmore ^* has done for birds from the eastern Carolines 

 and other Pacific islands. 



I am convinced, however, that Mathews ^^ is in error in regarding 

 the white plumage as a separate species from the dark. The series 

 before me seems to indicate that the white birds are only immatures 

 or at most only a phase of the slate-colored birds. There are several 

 specimens in pied plumage, and even amongst the dark birds there 

 are at least two plumages — the well-known slate-colored adult and a 

 lighter-colored bird with considerable admixture of brownish feath- 

 ers in the plumage. The Celebes specimens, listed above, illustrate 

 the two phases of the dark plumage, and all indications point to the 

 lighter-colored bird being immature. It lacks the elongate scapular 

 plumes, and the other specimens in this plumage are similar; one of 

 the inner secondaries of the left wing is edged with white at the tip. 

 Of course the absence of the elongate scapular plumes may be due 

 to the nonbreeding season, but the general body plumage has the 

 fluffy appearance of immaturity which can be better told than de- 

 scribed. The evidence seems to show that the species goes through 

 several plumage changes; that it breeds in the white phase is no 

 doubt true, but this does not prove that it is a different species. Sev- 

 eral North American -herons have more than one phase of plumage; 

 DichroTnanassa rufescens^ for instance, and the young of Florida 

 caeruXea are always white, eventually assuming the slate plumage of 

 the adults. 



64. NYCTICORAX MANILLENSIS MINAHASSAE Meyer and Wiglesworth. 



One adult male, one adult female, and one immature female, Likoe- 

 pang, February 22 and 24, 1916. 



The above two adults when compared with two adult males and 

 three adult females from the Philippines differ as follows: They 

 have a pronounced whitish superciliary; the throats are broadly 

 white, and this white continues down the foreneck in a narrow unin- 

 terrupted line until it merges into the white of the breast. In the 

 Philippine bird the superciliary is narrow and poorly defined (in one 

 specimen entirely absent) and cinnamon-rufous; the throats not pure 

 white and in one specimen from Luzon (No. 211274) with no white 

 at all; and there is no white line down the foreneck. In fact, the 

 Celebes bird forms a transition toward Nycticorax calcdonicus but 



6* Bull. Mus. Comp. Zool., vol. 63, No. 4, 1919, p. 171. 

 ^ Birds Australia, vol. 3, pt 6, 1914, p. 456. 



