118 THE BLACK TERN. 



Adult, 9, 24. Young, in autumn, 7§; wing, 9 T 8 2. 



Arrives in Texas from the south early in spring, proceeds along the coast 

 to the Mississippi, then ascends that river and its tributaries, breeding around 

 ponds, or along the streams; and even advances to the Fur Countries, where 

 it also breeds. Abundant. Migratory. Occasionally along the coasts of 

 the Middle Atlantic Districts. 



Adult Male. 



Bill about the same length as the head, slender, tapering, compressed, 

 nearly straight, very acute. Upper mandible with the dorsal line slightly 

 arched, the ridge convex at the base, narrowed towards the end, the sides 

 sloping at the base, slightly convex and nearly perpendicular towards the tip, 

 the edges sharp, the tip acute. Nasal groove reaching nearly to the middle 

 of the mandible; nostrils basal, linear, direct, pervious. Lower mandible 

 with the angle very narrow, acute, extending beyond the middle, the dorsal 

 line straight, the sides erect and slightly convex, the edges sharp and slightly 

 inflected, the tip extremely acute. 



Head of moderate size, oblong; neck rather short; body slender. Feet 

 small; tibia bare for a short space; tarsus very short, covered anteriorly with 

 small scutella, laterally and behind with reticular scales; toes very slender, 

 the first extremely small, the third longest, the fourth nearly as long, the 

 second much shorter, all scutellate above, the anterior connected by short 

 reticulate webs, having a concave margin, and not extending much beyond 

 the middle of the toes. Claws long, slender, arched, compressed, acute, that 

 of hind toe smallest, of middle toe largest, and having a thin dilated inner 

 edge. 



Plumage soft, close, blended, on the head short, on the back somewhat 

 compact. Wings very long, narrow and pointed; primary quills tapering, 

 the outer slightly curved inwards at the end, the first longest, the rest rapidly 

 graduated; secondary short, broad, incurved, rounded. Tail of moderate 

 length, emarginate, of twelve rounded feathers. 



Bill brownish-black. Iris brown. Feet reddish-brown, claws black. 

 Head, neck, breast, sides and abdomen, greyish-black; lower tail-coverts 

 white, lower wing-coverts bluish-grey. The general colour of the upper 

 parts is dark bluish-grey; the outer web of the first quill greyish-black. 



Length to end of tail 9 inches, to end of wings 11; extent of wings 24; 

 wing from flexure 8|; tail 3^-; bill along the back lj^, along the edge of 

 lower mandible 1 T S 2-; tarsus T 8 2-; middle toe j\, its claw -f-f . Weight 3 oz. 

 Young Male in autumn. 



The bill, iris, and feet, nearly as in the adult. The upper parts are grey- 

 ish-blue, the feathers of the fore part of the back, and especially the scapu- 

 lars, brown towards the end; the upper and hind part of the head greyish- 



