MUSEUM OF COMPARATIVE ZOOLOGY. 155 



traveller at every step, constantly changing in species with the increase 

 of altitude. Gradually, as one approaches the Park, the variety of 

 species diminishes, the timber becomes more scanty, and on every hand 

 there are evidences of increasing aridity in the climate. The birds 

 also decrease in number and in species, till finally we enter South Park 

 at its northern extremity by a pass having an elevation of about 10,500 

 feet, and an alpine fauna and flora. A few species of birds * were last 

 seen as we entered the mountains, and others disappeared higher up, 

 where still others were for the first time observed. 



Between South Park aud Pike's Peak the country is much drier than 

 that portion of the mountains between South Park and Denver. Leav- 

 ing South Park at its southeastern edge, the road thence eastward to 

 Colorado City, at the eastern base of Pike's Peak, passes through a 

 succession of open park-like tracts of country, covered with short grass. 

 The hills are low and rather scantily timbered, and the whole aspect 

 more or less arid and forbidding. The flora and fauna are far from 

 rich, the birds being mainly such as are found in South Park itself, 

 and the herbaceous vegetation also much the same. 



TURDIDJE. 



1. Turdus migratorius. Common everywhere. 



2. Turdus Pallasi. Frequent about Fairplay, and also observed at other 

 points. 



The Veery (Turdus fuscescens), although not observed in or about the 

 Park, was met with at several points between Denver and the Park, espe- 

 cially along the North Fork of the South Platte. 



SAXICOLID^I. 



3. Sialia arctica. Common everywhere. 



PARIDJE. 



4. Parus atricapillus. A small party were met with at Fairplay, rep- 

 resenting of course the septentrionalis race, characterized mainly by lighter 

 colors, and more especially by a broader edging of white on the quills. 



TROGLODYTID^J. 



5. Troglodytes aedon. Common. 



SYLVICOLIDJE. 



6. Dendrceca Auduboni. Common along the streams and timbered 

 ridges. 



* Pipiln eryikrophthalmu8, var. arcticus, Harporhynchus rufus, Mimus carolinensis, 

 Icteria virens, etc. 



