AUGUST, 1915. NOTES ON SOUTH AMERICAN BIRDS CORY. 313 



where two or more subspecies meet,* or, in regions where such varia- 

 tion is the exception, to a tendency to atavism or reversion towards an 

 ancient type from which they have become more or less differentiated 

 by difference in environment. Specimens from other parts of South 

 America, however, do not show such extreme variability in this char- 

 acter; in fact deviation from the regional type is seemingly the exception. 

 In the series of specimens from Peru and Chile the normal coloration of 

 the inner web of the outer rectrix posterior to the subterminal black band 

 seems to be rufous, as it is so represented in 20 out of 24 specimens from 

 those regions. On the other hand, out of 20 males from the Provinces of 

 Matto Grosso and Bahia, Brazil, 16 have the inner web of the outer 

 rectrix alternately barred with black and white without rufous; 3 have 

 it part white and part rufous, and only one shows the rufous coloration 

 as in the normal Chilean bird. All of the males which I have seen from 

 Margarita I. and 7 of the 9 from Curacao and Aruba have the inner 

 web of the outer rectrix (posterior to the subterminal black bar) barred 

 with black and white. In two from Curacao it is variegated, being 

 part rufous and part white, while in all the specimens from the Rio 

 Branco region, northern Brazil (7 males from Boa Vista), it is plain 

 rufous. 



6. That the variation in length of the subterminal black zone or 

 band on the rectrices seems to represent a good racial character, being 

 very short in cinnamomma from Chile, strikingly long in ochracea from 

 northern Colombia and northern Venezuela, and showing a gradual 

 gradation in intermediate races. 



7. That the absence or presence, as well as the size and number, of 

 the white spots on the outer webs of some of the outer primaries repre- 

 sents a good distinguishing character in some races. 



8. That there is comparatively little individual variation in the 

 intensity of the coloration of the under parts in adults of the same sub- 

 species, but that immature birds are paler. In very young males the 

 gray wing coverts are tipped with rufous buff and the inner primaries 

 strongly tipped with white or whitish. 



9. That the configuration and confluence or non-confluence of the 

 distal white patches on the inner webs of the outer primaries seem to be 

 too variable to be of value in diagnosis, and apparently have no depend- 

 able racial significance. For example, in one of the eight specimens 

 of peruviana now before me, none of the markings are confluent; in two 



* A possible analogy suggests itself in the case of Colaptes auratus luteus and 

 Colaptes caffer collaris in the Yellowstone and Black Hills regions in North America, 

 where great irregularities in coloration are very frequent, abnormally colored speci- 

 mens approaching the California form, C. c. collaris, being also occasionally found 

 east of the Mississippi River and vice versa. 



