54 BULLETIN 159, UNITED STATES NATIONAL MUSEUM 



Adult male, U.S.N.M. No. 174708, Sirhassen Island, June 1, 1900, 

 "Toes leaden; tarsi greenish." 



Adult male, U.S.N.M. No. 174712, Sirhassen Island, June 1, 1900. 

 "Bill leaden blue, tip black; feet leaden, claws black." 



Adult male, U.S.N.M. No. 174714, Sirhassen Island, June 9, 1900. 



Adult male. U.S.N.M. No. 174717, Pulo Subi, June 13, 1900. 

 "BOl leaden, tip black; feet leaden." 



Adult male, U.S.N.M. No. 174715, Bunguran Island, June 28,. 

 1900. "Feet leaden blue." 



Adult male, U.S.N.M. No. 174716, Bunguran Island, June 28, 1900. 



Adult female, U.S.N.M. No. 174711, Sirhassen Island, June 1, 1900. 

 "Feet leaden; iris dark brown." 



Adult female, U.S.N.M. No. 174709, Sirhassen Island, June 1,. 

 1900. "Iris dark brown; bill leaden, black at tip; feet leaden blue." 



All these except three (Nos. 174712, 174713, and 174717) show the 

 beginnings of molt among the feathers of head, throat, or hind neck, 

 but in most of the individuals it is not evident without close examina- 

 tion, and in no case has it yet involved the wing quills or rectrices. 



Measurements are given in Table 14. 



Birds of this species from the Natuna Islands were referred pro- 

 visionally to the Philippine race, Artamus leucoryn. leucoryn., by 

 Doctor Stresemann,^' but comparison of the present 10 adults with a 

 large series of Philippine specimens indicates that there are subspecific 

 differences between them. The Natuna birds are accordingly here 

 separated as a new race, though not on the characters mentioned by 

 Doctor Stresemann. The chief individual variation among the 

 Natuna birds is in the depth of color on the head, and in the more 

 sooty or slaty shade of the back and scapulars, although this latter, 

 while producing an occasional specimen difficult to distinguish in 

 color from Philippine birds, yet does not vitiate the character of more 

 distinctly brownish back shown by the Natuna series as a whole. Birds 

 from Borneo are referable to the typical race. So far as known, 

 Artamus leucoryn. macroterus is thus confined to the Natuna Islands. 



Doctor Abbott says that on Sirhassen Island it frequents thin 

 scrub and open ground and makes use of dead trees as perching places. 



A comprehensive review of all the other subspecies of Artamus leu- 

 coryn. has been published by Dr. Erwin Strescm.aun.^^ 



•' Nov. Zool., vol. 20, no. 2, p. 290, June 17, 1913. 



M Nov. Zool., vol. 20, no. 2, pp. 289-293, June 17, 1913. 



