596 ROUGH-WINGED SWALLOW. 
toes are somewhat longer and more slender, and there are no feathers 
on the hind part of the tarsus as in the common species; the claws 
are much more slender. 
The bill is black, the tarsi, toes, and claws dusky. The upper 
parts are of the same greyish-brown, or mouse-colour, as those of the 
Bank Swallow. The lower are of a very light greyish-brown, gradually 
paler on the hind parts, the abdomen and lower tail-coverts being 
white. 
Length to end of tail 52 inches, to end of wings 6}; extent of 
wings 12}; bill along the ridge #4, along the edge of lower mandible 
& ; wing from flexure 4;‘,; tail to end of middle feather 1}$, to end of 
longest feather 2; tarsus 7%, ; hind toe 7, its claw 7+ ; middle toe 7%, 
its claw #. 
In a specimen, from Charleston, South Carolina, preserved in spi- 
rits, the roof of the mouth is flat, the width of the gape 53 twelfths ; 
the tongue triangular, 3} twelfths long, emarginate and papillate at 
the base, with two of the papilla much larger, flat above, tapering to a 
slit point, more narrow and elongated than that of the Sand Swallow. 
The cesophagus is 1 inch 11 twelfths long, without dilatation, its 
breadth 14 twelfth. The stomach is elliptical, muscular, 5 twelfths 
long, being 43 twelfths, and placed a little obliquely ; the epithelium 
brownish-red, tough, longitudinally rugous, filled with remains of in- 
sects. The intestine is 44 inches long; the cceca 14 twelfth in length, 
and 8 twelfths distant from the anus. 
The trachea is 1 inch 4 twelfths long, its diameter 1 twelfth ; its 
rings about 50; the muscles as in the other species; the bronchi very 
slender, of about 12 half rings. 
