88 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



betweeu the species of each gioup, which is a much more difficulL matter. 

 Passing by group A., which contains only S. nudipcs, the three species 

 belonging to group B. may be distinguished as follows : — 



a. — Toes stout, with strong claws. Wing exceeding .5.75 inches (rare- 

 ly less than 6.00, and ranging to nearly 8.00 inches) ; tail 

 more than 3.15 '2. A. brasilianus. 



b. — Toes weak aud slender, with weak claws. Wing less than 5.75 

 inches (ranging in length from 5.10 to 5.60) ; tail less than 

 3.15 (2.60-3.10). 

 Feathers of the outer margin of the face with their shafts pro 

 duced into slender, soft, hair-like, curved bristles, forming a 

 conspicuous rufi",the anterior side concave. Plumage coarsely 



spotted . above aud below 3. S. ha rharus. 



Feathers of the outer margin of the face with their shafts not 

 conspicuously developed. Plumage finelj' vermiculated, 

 above and below, the outer scapulars having orange-baflf 

 spots on the outer webs 4. >'. Ilammcolux. 



The above brief diagnoses are probably sufficient to distinguish these 

 three very distinct species iu all their numerous variations. The differ- 

 ences are very much more easily perceived than defined, the birds having 

 an entirely different aspect when compared with one another. Of the 

 three, S. brasilianus varies almost indefinitely, but may always be 

 known by its much stouter toes and stronger claws, as well as by its 

 larger size, even in the smallest race {S. cassini), although the differ- 

 ence in dimensions is sometimes so slight as to be perceptible only 

 by actual measurement. S. harharus is distinguished by the coarseness 

 of its markings, which partake of the character of roundish or trans- 

 versely-oblong spots, rather i han fine vermiculations,and by the peculiar 

 development of the shafts of the facial feathers. ^\ Jiamnicolus is 

 slightly sujaller than (S. barbarus, and of quite different build, having 

 an extremely light and slender body, with small head, the wings thus 

 seeming very long in proportion. As to colors, it may ordinarily be 

 distinguished froai all the other species by the pronounced orange-buff 

 tint of the outer webs of the outer row of scapulars, these being in most 

 others white, or, if not v. bite, of a more sombre shade of buff" and ful- 

 vous, the plumage being otherwise quite different. According to 3Irs. 

 M. A. Maxwell, who has in her finely -mounted collection of Colorado 

 birds a very beautiful specimen, the iris of this species is of a deep 

 hazel, or umber-brown ; should this prove constant, it wall afford an 

 excellent character, since the iris in nearly if not all the other species is 

 known to be a bright lemon-, or gamboge-, yellow. 



