232 PatmerR, The Maryland Yellow-throat. cae 
The longer tails of the most southern specimens of roscoe, and 
of melanops, point to a sub-tropical and almost sedentary life; 
while the shorter tails and longer wings of far northern birds show 
results due to migration. 
Lntergrades. 
The first Yellow-throats to appear about Washington in the 
spring migration are true ¢richas, later larger birds appear, the 
latest migrants being brachidactyla. During August ¢richas, both 
adult and young, move southward and gradually are replaced by 
larger birds, so that by September 1 the summer residents have 
wholly disappeared and a larger intermediate lot of birds are 
abundant, especially about the marshes. These are followed 
during the month by still larger birds with longer wings and 
longer outer primaries, so that October specimens are almost 
always typical drachidactyla. The proportion of good brachidac- 
tyla is much less than of ¢v?chas or of intermediates, as the latter 
loiter on the southward journey, while the former with a much 
longer journey in view make fewer stops. Their main bulk, 
however, journey coastwise. Specimens from the vicinity of 
New York and Long Island, while not perfectly typical drachi- 
dactyla, are constantly so different from typical ¢vzchas as to be 
placed with the former. 
About Washington true /¢richas frequents the roadsides, the 
marshes and small low bushy places on the hillsides. The 
intermediates almost entirely frequent the marshes, while the 
larger brachidactyla nearly always is found in ravines and along 
streams in the deep woods. 
The Mississippi Valley bird really is an intermediate, nearer 
trichas in the middle and eastern areas of the valley, nearer 
brachidactyla northward and northeastward, while along the 
eastern edge of the plains it merges into occidentalis; this result 
having been most evidently produced by the gradual disappear- 
ance of the Mississippi Sea. . 
The birds of the Dismal Swamp are not quite typical roscoe, 
but decidedly are not “vichas. The birds of Virginia Beach, east 
of Norfolk, are similar. On the opposite shores of Chesapeake 
