BIRDS OF PENNSYLVANIA. 257 



GENUS STELGIDOPTERYX BAIRD. 

 Stelgidopteryx serripennis (AuD.). 



Rough -winged Swallow. 



DESCRIPTION. 



Rather larger than the last ; bill, legs and eyes same color as the Bank Swallow ; 

 above grayish-brown ; lower parts similar, though paler, gradually whitening on 

 the belly ; edge of first primary rough to the touch, by the outer web being con- 

 verted into a series of stiff recurved hooks. The design of this peculiar wing struc- 

 ture is not clearly known. It has been suggested that these hooks "assist the birds 

 in crawling into their holes, and in clinging to vertical or overhanging surfaces." 

 Coues. 



Habitat. United States at large (in the Eastern States north to Connecticut), south 

 to Guatemala. 



The Bank and Bough-winged Swallows arrive here about the first 

 week in April and remain with us until about September 1. Both spe- 

 cies frequent the same localities, being- found generally in the neighbor- 

 hood of rivers, large creeks and mill-dams. These birds are not only 

 alike in habit, but they also greatly resemble each other in size and 

 colors. The Bank Swallow has a white throat and a dark band across 

 the breast. The Rough- winged has a uniform mouse-colored throat and 

 breast. These throat and breast markings will sometimes enable you 

 to recognize the birds in life. Should you, however, desire to positively 

 determine these two species, my advice would be, take your gun and 

 shoot them. After doing this you will know the Bank Swallow by a 

 tuft of feathers on the tarsus, near the insertion of the hind toe. An 

 adult Rough-wing (particularly if an old male) has the first wing quills 

 furnished with a number of saw-like hooks, from which originate the 

 common name, likewise the technical one, serripennis, but as the imma- 

 ture Rough-winged Swallows lack these curious hooks, look at their legs 

 a Rough-winged Swallow has no feathers on the leg just above the 

 hind toe. 



FAMILY AMPELID-ffi. WAXWINGS. 



THE WAXWINGS.* 



Two birds of this family are found in Pennsylvania. The Cedar-bird is a com- 

 mon resident and occurs in all parts of the state, but the Bohemian Wax wing is a very 

 rare and irregular visitor from the north, and is usually seen here only in exces- 

 sively severe winters. Wax wings are nearly always observed in flocks. The sexes 

 are alike ; the tails are tipped with yellow. The wings are long and pointed ; first 

 quill very short ; second and third longest ; the under coverts extend almost to the 

 end of the even tail ; the wings and tips of some tail feathers in many individuals are 

 often furnished with horny appendages, like red sealing wax ; bill broad, short, 

 wide at base, notched and slightly hooked at tip. Feet rather small and weak ; 

 three toes in front and one behind. 



* Dr. Coues (Birds of Colorado Valley) referring to the ' sealing-wax " appendages of the secondary 

 quills of birds of this genus, says they have been subjected to chemical and microscopical examination 

 by L. Stieda, and shown to be the enlarged, hardened and peculiarly modified prolongation of the shaft 

 itself of the feather, composed of central and peripheral substances, differing in the shape of the pigment 

 cells, which contain abundance of red and yellow mlm-ing matter. '' 



17 BIRDS. 



