74 
RICHARDSON'S JAGER. 
Male, 18J, 40. Young, in September, 15£ ; wing, II4. 
Coast of Massachusetts and Maine, during winter. Breeds in the 
northern barren grounds, away from the coast. 
Adult Male in spring. 
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, sub-marginal, pervious, linear-oblong, wider 
anteriorly. Lower mandible with the angle long and narrow, a slight 
prominence at its extremity, beyond which the dorsal line is straight and 
ascending, the sides sloping outwards and convex, the edges sharp and 
inflected, the tip obliquely truncate and rather obtuse. 
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 
prominent 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 a little shorter, the second con- 
siderably 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 feathers 
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, obliquely 
rounded. Tail feathers of moderate length, excepting the two middle, 
which extend beyond the rest and taper to a point, the other feathers broad 
and rounded, there being twelve in all. 
Bill greyish-black, the upper part bluish. Iris brown. Legs and feet 
black. The general colour of the plumage is of a sooty-brown, the upper 
part of the head, the primary quills, and the tail darker, the breast and 
abdomen lighter ; the shafts of the primary quills white, of the tail feathers 
brownish. 
Length to end of tail 18 £ inches, to end of wings 17 ; extent of wings 40 ; 
wing from flexure 12f ; tail 85, the middle feathers 2f longer than the 
rest ; bill along the back 1 T V, along the edge of lower mandible If ; tarsus 
l r V ; middle toe lfV, its claw T 4 5 . 
