472 ARCTIC JAGER. 



Lestris Buffonii, Ch. Bonaparte, Synopsis of Birds of the United States, p. 364- 

 Lesthis parasitica, Arctic Jagek, Swains, and Richards. Fauna Bor. Amer. partii. 



p. 430. 

 Arctic Jager, Nuttall, Manual, vol. ii. p. 317. 



Adult Male. Plate CCLXVII. Fig. 1. 



Bill about the length of the head, rather slender, straight, the tip, 

 curved. Upper mandible with the dorsal line straight, toward the end 

 curved, the ridge broad and convex, the sides separated from the ridge 

 by a narrow groove, extremely narrow and convex, the edges sharp and 

 inflected, the tip compressed, rather obtuse. Nostrils in the fore part of 

 the nasal groove, nearer the tip than the base, submarginal, pervious, 

 linear, oblong, wider anteriorly. Lower mandible with the angle long 

 and narrow, a slight prominence at its extremity, beyond which the dor- 

 sal line is straight and ascending, the sides sloping outwards and convex, 

 the edges sharp and inflected, the tip obliquely truncate and rather ob- 

 tuse. 



Head rather small, oblong, much narrowed before. Neck of moderate 

 length. Body rather slender. Feet rather short and of moderate strength ; 

 tibia bare at its lower part ; tarsus anteriorly covered with broad decurved 

 scutella, on the sides with oblong scales, behind with smaller oblong pro- 

 minent scales ; hind toe extremely small and elevated, the fore toes of 

 moderate size, connected by reticulated webs, which have their margins 

 convex ; the third toe longest, the fourth not much shorter, all covered 

 above with numerous scutella, the lateral ones margined externally with 

 small prominent scales directed forwards. Claws of moderate size, curved, 

 acute, compressed, that of third toe with a sharp inner edge. 



The plumage in general is close, elastic, soft, and blended ; the fea- 

 thers on the back and wings rather compact and distinct. Wings very 

 long, rather broad, pointed ; primary quills tapering and rounded, the 

 first longest, the rest rapidly graduated ; secondary rather short, round- 

 ed. Tail feathers of moderate length excepting the two middle, which are 

 extremely elongated and gradually attenuated, the rest broad and round- 

 ed, there being twelve in all. 



Bill greyish-black, the upper part bluish. Iris brown. Feet black, 

 but with the greater part of the tarsus yellow. The neck and lower parts 

 are white, the former tinged with yellow ; upper and fore part of head 



