56 EXPLORATIONS AND SURVEYS WEST OF 100TH MERIDIAN. 



number is of especial interest, as extending their range much farther to 

 the west than was hitherto known. The fauna in the vicinity of Den- 

 ver is perhaps best compared with the Carolinian of the Eastern 

 Province ; but the list presents quite a number, as would naturally be 

 expected from the early season at which the collection was made, which 

 are to be regarded merely as migrants, and which spend the summer 

 ar to the northward. The arrangement and nomenclature is in most 

 cases that adopted in the "Birds of North America," by Baird, Brewer, 

 and Eidgway. 



SECTION I. 



TURDID^E (the Thrushes). 



1. Turdus migratoriusj L. 



Quite common; a pair seen May 10, building their nest in the par- 

 tially open cavity of a tree. 



2. Turdus fuscescens, Stephens. Tawny Thrush. 



First seen May 17, after which it was daily noticed in small numbers 

 frequenting the moist thickets bordering the small creeks. 



3. Turdus swainsoni, Cabanis. Olive-backed Thrush. 



Several noticed May 12. By the 17th, this species fairly swarmed in 

 the same localities as the preceding. The females were apparently a 

 full week later than the males. 



4. Galeoscoptes carolinensis, (L.) Catbird. 

 Apparently not common; one seen May 14. 



