^1889."'] PROCEEDINGS OF THE NATIONAL MUSEUM. 5 



additional specimens would necessitate the recognition of at least two 

 geographical races in addition to the typical form. The specimens ex- 

 amined are as follows : 



- a. No. 36770, U. S. Nat. Mus., Eio de Janeiro; Natural History Museum of Rio 

 h. No. 36769, U. S. Nat. Mus., Rio de Janeiro; Natural History Museum of Rio. 



c. No. 24016, U. S. Nat. Mus., "South America (Cruise of the Delaware) Dr. G. R. 

 Horner." 



d. No. 24035, U. S. Nat. Mus., Sta. Catarina; Lemuel Wells. 



e. No. 116630, U. S. Nat. Mus., Sta, Catarina; Lemuel Wells. 

 /. No. 14726, U. S. Nat. Mus., Bueuos Ayres; J. K. Townsend. 



g. No. 17966, Mus. Corup. Zoology, Thayer expedition. (Locality not given.) 

 h. No. , Am. Mus. Nat. Hist., "Brazil?"; Lawreuco collection. 



Specimens a, b, c, and h are typical X. albicolUs, having the rump 

 and upper tail-coverts rusty-chestnut (the lower back, even, tinged with 

 the same), and the under surface strongly tinged with tawny. 



Specimens d and e (from Sta. Catarina) have the rump and upper 

 tail-coverts olivaceous-russet, only slightly tinged with rusty (this tinge 

 confined to upper tail-coverts in specimen d), the under parts much 

 less tawny, the buffy streaks on pileum slightly narrower and paler, and 

 the bill decidedly smaller and more slender, and uniform brownish black 

 in color, instead of having the under mandible (and sometimes terminal 

 portion of the upper) mostly horn-colored. 



Specimen g is nearly intermediate, having the more tawny under parts 

 of true X. albicolUs, the small, slender, wholly black bill of Sta. Cata- 

 rina specimens, and the color of the rump aud upper tail-coverts inter- 

 mediate between the two, or russet, becoming deeper on upper tail- 

 coverts. 



Specimen / (from Buenos Ayres) is particularly different in color 

 from true X. albicolUs, and unless the peculiar coloration may be due, 

 more or less, to exposure to the light (it haviug been mounted for many 

 years) is differeut enough to be considered specifically distinct. The 

 ground color of the pileum and hind-neck, instead of being black is dull 

 sepia brown, with the streaks dull buffy-whitish ; the back, scapulars, 

 and almost the whole of the outer surface of the closed wing are dull 

 grayish-brown or pale sepia, the lower back, rump, and upper tail-coverts 

 browner, but not approaching rusty, though the upper tail-coverts have 

 a tinge of light Mars-brown. The tail and the inner webs of the remiges 

 are dull chestnut, much lighter as well as duller than in typical X. al- 

 bicolUs ; the ground color of the under parts of the body is light gray- 

 ish-brown or broccoli-brown, the streaks dull whitish. Should other 

 examples from Buenos Ayres prove to be similar to this one, I propose 

 that the bird be called Xiphocolaptes argoitinus or X. albicolUs argen- 

 tinus. 



