^Tqo^^l Stone, Winter Cro-v Life in Dclaxvare Valley. 271 



series. In size the largest Fish Crow fails to equal the smallest 

 Common Crow, though exceptional examples approach more 

 closely in dimensions of wing than is generally supposed. The 

 bulk of the specimens, however, differ widely, and emphasize the 

 distinctness of these two species. Indeed, to my mind it is the 

 only distinct type of Crow in the United States apart from C. 

 americaniis, all the others, even C. caiirinns, being apparently geo- 

 graphic derivatives of the latter. The measur'ements of twenty- 

 five specimens are as follows : 



Wing, 956-11.55; average, 10.68 ins. 



Culmen, 1.41-1.63; average, r.52 ins. 



Bill from nostril, i. 02-1. 20 ; average, i.io ins. 



Some of the largest individuals are females, and there does not 

 seem to be much difference in the average size of the two sexes. 

 A series of fifteen Common Crows from the same vicinity yields 

 the following measurements, which will show the comparative 

 dimensions of the two species as found in the Delaware Valley in 

 winter. 



Wing, 1 1. 60-13. 35 ; average, 12. 28 ins. 



Culmen, 1.75-2.03; average, 1.86 ins. 



Bill from nostril, i. 25-1. 52; average, 1.34 ins. 



Tlie average size of the skulls of the two species is as follows ; 



C americanus, length, 3. 58 ins.; greatest breadth, 1.48 ins. 

 C. ossifrai^/is, length, 3.03 ins.; greatest breadth, 1.28 ins. 



