VOl 'l9i5 Xn ] Chapman, The Genus Scytalopus Gould. 407 



to birds like Scytalopus, not only because of their rarity in col- 

 lections, but because such birds, as a rule, show a greater tendency 

 to respond to the influences of their environment than do less 

 sedentary species. 



Of Scytalopus alone we have thus taken in Colombia eighty-two 

 specimens, doubtless a greater number than heretofore has been 

 known from that country. Of Scytalopus microptcrus microptcrus 

 Scl., for example, the British Museum contained but four specimens 

 when Sclater published his monograph of this genus. Prior to our 

 work in Colombia the American Museum contained but one speci- 

 men of this species, and at the present time the Museum of Compar- 

 ative Zoology contains but two, making a total of seven specimens 

 for three large Museums. 



In view of these facts one might well believe that Scytalopus 

 m icropterus was a rare species, but without making a greater effort 

 to secure this bird than any other of similar habits, we have never- 

 theless obtained a series of twenty-four specimens. This includes 

 both juvenal and adult plumages and, for the first time, enables one 

 to determine that the silvery-white crown-patch, which is so strik- 

 ing a feature of some specimens, is purely individual and is not 

 associated with either age or sex. 



I give these figures for what I believe to be their significance, as 

 in a general way they indicate how much field-work we still have to 

 do before our collections of South American birds approach any- 

 thing like completeness, rather than for their restricted application 

 to the case in point. 



Without attempting a revision of the entire genus, for which in- 

 deed adequate material does not yet exist in Museums, I give below 

 the results reached in preparing a report on our Colombian speci- 

 mens for inclusion in a paper on the distribution of bird-life in that 

 country now in course of preparation. 



In addition to the eighty-two Colombian specimens mentioned, 

 W. B. Richardson has recently collected for us seven specimens in 

 Ecuador, and Anthony and Ball, in April last, collected ten speci- 

 mens of a most interesting new species in eastern Panama. 



Of high importance is a series of thirteen topotypical specimens 

 of S. magellanicus (Gmel.) lately received by the Brewster-Sanford 

 Collection from Beck, which in connection with a Chilean specimen 



