98 Zoology of Colorado 



head, living principally in the region of the pinyon pines. The 

 Plumbeous Bush Tit (Psaltriparus plumbeus of Baird) is a small 

 bird, less than four and one-half inches long, with no black on 

 crown or throat. It is mainly found in the southern and western 

 parts of Colorado, and is by no means common. It inhabits the 

 same sort of country as the Gray Titmouse. Our Mountain 

 Chickadees, of the genus Penthestes, are the Mountain Chickadee 

 (P. gambeli) with a conspicuous white stripe above the eye, and 

 the Long-tailed Chickadee, (P. atricapillus septenlrionalis) with- 

 out such a stripe, the crown being solid black down to the level 

 of the eye. 



SYLVIIDAE 



The Sylviidae, which include the true Warblers of Europe, 

 send some offshoots to America, where they almost seem out of 

 place. In the Indian region, as recently so well described by 

 Stuart Baker, there are 33 genera. The minute Kinglets (Regulus) 

 are circumpolar. Our common one is the Ruby-crowned Kinglet, 

 R. (or Corthylid) calendula, the crown in the male with a red spot, 

 but no black, in the female merely clouded like the back. Very 

 much rarer is the Western Golden-crowned Kinglet, R. (or 

 Orchilus) olivaceus, considered by some to be a subspecies of the 

 common European bird, R. regulus. It has the crown with orange 

 or yellow bordered by black. The genus Polioptila of P. L. 

 Sclater* represents a special subfamily. The Western Gnat- 

 catcher (P. caerulea obscura of Ridgway) is a rather slender bird 

 about four and one-half inches long, grayish blue above, with a 

 black V-shaped band across the forehead; the tail is black and 

 white. It is a rare summer bird on the plains. 



TURDIDAE 



The thrush family is very widely spread over the world, but 

 most likely had its origin in the Eastern Hemisphere.** However 

 that may be, it has given rise to some distinct types in America, 

 the most interesting being Sialia, the genus of bluebirds. Our 



*Dr. P. L. Sclater, for many years secretary of the Zoological Society of London, was 

 the author of innumerable important works on birds and mammals. W. L. Sclater is his son. 



**The Old World Prunellinae, with scutellated tarsus, appear to be more primitive than 

 any of our American birds. 



