WILSON'S TERN. 547 



Description. 



Adult. — Upper part of the liead and hind neck deep-bla'ck, tinged with brown 

 on the front part of the head; back and wings light grayinh-hlue; first primary 

 with tiie outer web black, on the inner web grayish-black next the shaft, this color 

 increasing in extent towards the end, where it covers the entire web for about one 

 incii, rest of inner web white; the next five primaries are hoary on their outer webs, 

 and blackish-graj' on the inner next the shaft, occupying the entire web at the end ; 

 margin of the inner webs white ; central tail feathers very pale bluish-gray, the others 

 white on the inner webs and dusky-gray on the outer webs, deepening in color frc>m 

 the central feathers until it becomes blackish-gray on the lateral ones; sides of the 

 head, throat, rump, and under tail coverts, white ; breast and abdomen clear pearl- 

 gray; bill coral-red, black near the end with the tip yellow; iris hazel; legs and 

 feet coral-red, not so dark as the bill; claws brownish-black. 



Length, fourteen and three-quarters inches; wing, ten and three-quarters; tail, 

 five and three-quarters; bill, one and three-eighths; tarsus, three-quarters of an 

 inch. 



Hah. — Texas to Labrador. 



This is by far tlie most common species we have in New 

 England. It breeds in great abundance all along onr coast, 

 both on the beach, on the mainland, and on the rocky and 

 sandy islands off our shores. In some localities, it is so 

 abundant that I have collected in the space of two hours, 

 in the area of about thirty acres, a half-bnshel of eggs. In 

 most localities, it forms no nest, but drops its eggs on the 

 sand or on the bare rock. On the island of Muskegeet, I 

 found that it invariably scooped out a hollow of two or three 

 inches in the sand, in which it laid three or four eggs, 

 arranged them with their small ends together in the middle, 

 and built around them a loose nest of seaweeds and grass. 

 These eggs are so varied in color and markings, tliat no 

 description of them can be given by which they may be recog- 

 nized. In a great number in my collection, the predominat- 

 ing color is a reddish-drab, which is marked with numerous 

 spots and confluent blotches of different shades of brown, 

 and obscure blotches of cinereous. Many specimens are an 

 olivaceous-gray, with the same markings ; and others are a 

 creamy-buff. Their form is usually exactly ovoidal, and 

 their dimensions average about 1.55 by 1.25 inch. 



This species is very irregular in its period of depositing 

 its eggs. I have found them as earlv as the last week in 



