Jeffkies on the Ipswich Sparrow. 
105 
month. By December the princeps in their turn move south, a few re- 
maining through the winter. 
If we regard princeps as merely a Northern form or variety of P. savanna , 
in what ought we to expect it to differ from the typical form ? First, it 
should be of greater size ; second, it should be of lighter color, but have 
the same style of coloration. 
First, as to size, princeps is undeniably larger on the average than 
Savanna Sparrows shot in Massachusetts, but not so decidedly as I had 
inferred from published measurements. The following table shows that 
specimens of princeps intergrade with typical savanna in size, while the 
average size of princeps is smaller than var. sandwicliensis as given in 
“ History of North American Birds ” : — 
M easurements .* 
* 
ZfJ 
Alar extent. 
Length, Fresh. 
fl 
•l-H 
& 
Tarsus. 
Mid. Toe and Claw. 
Bill along Gape. 
Date of 
Capture. 
Remarks. 
P. princeps 
9 
9.50 
6 25 
3.10 
.90 
.87 
.53 
Nov. 9, 1878 
Largest specimen. 
Cl U 
9 
9.06 
5.88 
2.79 
.80 
.81 
.52 
Nov. 28, 1878 
Small specimen. 
c i cc 
9.63f 
6.05t 2.96 
89 
.89 .53 
Average of 17 specimens. 
CC ll 
11 00 
6.25 
3.28 
.95 
From Maynard’s “ Birds of 
Florida.” 
“ savanna var. 
. ' 
From Baird. Brewer, and 
sandwichensis 
6.12 
3.10 
.56 
Ridgway’s “ History North 
American Birds.” 
“ savanna 
<? 
9 50 
6.00 
2 82 
.87 
.80 .52 
April 24, 1875 
• 
* All of the specimens of Passerculus prinreps were taken either at Marblehead or Swampscott. 
Four are in Mr. Brewster’s collection, and the remaining fifteen in that of Mr. J. A. Jeffries, 
t Average of eleven specimens. 
Certainly princeps is not distinguishable from savanna by its larger size, 
since it is generally smaller than that variety which lives in the North- 
west. In the above table most weight is given to length of wing, that 
being the measurement least liable to vary with the person measuring. 
Secondly, princeps, the Northern race, should be the lighter. Here we 
have one of the characteristics given as easily distinguishing princeps from 
savanna. The plan of coloration is alike in both forms throughout, the 
variation being simply one of intensity of color. The color of the ventral 
surface of both birds is often identical. The yellow superciliary stripe 
varies with season, and in different individuals, sometimes there being no 
yellow, while again it is very marked. One point in which extreme speci- 
mens seem to differ is, that savanna has a good deal of buff on the sides 
of the head, breast, and flanks ; the whole back also shows this buffy 
tinge ; while a light princeps shows very little of it, if any. Intermediate 
specimens, however, grade one into the other. It so happens that we 
have an excellent parallel of this coloration in our Thrushes, the Southern 
form of. Tardus sivainsoni showing a very similar suffusion on the sides of 
