l62 



SUMMER BIRDS. 



rested, and his investigation disclosed the fact that the mosses which 

 abounded immediately about the nest had not been utilized as build- 

 ing material. As determined by Professor Eaton, the species of 

 moss composing the bed were : Hypnuni iiiubvatuni. H. splcndcns, 

 H. Schreberi, H. Crista-castrcnsis. Those appearing in the nest : 

 Hypnum Midler ianu7n, H. Muhlenbeckii {? ) . Dicraniun longifoliinn, 

 D. flagdlare. PolytricJuim commune, P. formosum. With these oc- 

 curred the following Hepaticae : Mastigobryiim trilobatiLm, Scapania 

 albicans, CcpJialozia biciispidata. In addition were found among the 

 materials of construction, catkin scales of the birch, leaves of the 

 balsam, and fragments of the dried pinnae of ferns, but, as suggested 

 by Professor Eaton, the presence of some of these was probably 

 accidental. Springing from the verdant moss beds immediately 

 about the nest were scattered plants of Oxalis aceiosella, Tri entails 

 Americana, Solidago thyrsoidea, and Clintonia borealis. 



It is rather surprising to find specimens of the Yellow-bellied Fly- 

 catcher — undoubtedly a bird of the Canadian Fauna '^' — from southern 

 New York to be of large size for the species. We might well have 

 expected the reverse to be the case, and the fact of maximum spe- 

 cific size th\is obtaining at. so far as we now know, the southernmost 

 breeding limit of the species, illustrates well the close correspondence 

 between the conditions imposed by altitude and by more advanced 

 latitude without elevation, on organic nature. 



The following measurements and comparison will show the relative 

 size of the Catskill birds with the largest examples of eleven specimens 

 taken on the migrations at New York. 



New York Specimens. 



* That this bird has been suspected to breed in regions thoroughly Alleghanian or even more 

 southern in Fauna, is to be accounted for from the fact that the times of its migration are such as 

 might easily give rise to the impression. The species is one of the latest of the migrants to remain 

 with us in the spring, and one of the first to reappear on the return movement. Thus, in the neigh- 

 borhood of New York, where it occurrs strictly as a transient semi-annual migrant, it remains, 

 on the advance movement, sometimes into June, and is always to be again looked for early in 

 August ; and, though I have no actual July records, individuals doubtless somstime-; appear by the 

 latter part of that month. 



