

NATATORES. 437 



ican Crow taken from the nest. On such occasions, it does not 

 disgorge its food, like the Cayenne Tern and other species, 

 although it bites severely, with quickly repeated movements of 

 the bill, which, on missing the object aimed at, snaps like that of 

 our larger Fly-Catchers." Length about sixteen inches. 



The SILVERY or LITTLE TERN, S. argentea, (Lat. silvery,) is 

 closely allied to the S. minuta, (Lat. small or minute,) of Europe. 

 The upper parts and tail, are a deep pearl gray ; all beneath, 

 silvery white. It is larger than the corresponding European 

 species, and the entire upper parts, (with the tail,) are of a lighter 

 shade. Length from nine to ten inches. The eggs are light 

 yellowish white, with angular dark brown spots. The Silvery 

 Tern breeds from Texas to Labrador. 



THREE-TOED GULLS. 



The GULLS, Larus, are represented by thirteen or more species 

 on this continent. In these the hind toe is very small, and artic- 

 ulated high up on the tarsus ; in one species entirely wanting. 



The GREAT BLACK-BACKED GULL, L. marinus, is the largest 

 Gull that is seen on the American coast, and described as ex- 

 ceedingly bold, voracious, and predatory in its habits. Its length 

 is from twenty-eight to thirty inches ; the expanse of wings about 

 five feet and a half. It breeds on the coast, from Labrador 

 northwardly ; ranging in the winter, to New York, and migra- 

 ting as far South as Florida. It is also common in many parts 

 of the North of Europe, where it finds a home. Its nest is made 

 of grass, rushes, and other materials, and contains three or four 

 eggs, of an olive green, marked with very dark brown. Audu- 

 bon remarks, "This bird must be of extraordinary longevity, as 

 I have seen one that was kept in captivity more than thirty 

 years." The back and wings are a deep bluish black ; the 

 quills, with black shafts, tipped with white; in the summer, the 

 head and neck are pure white ; in winter, the same parts are 

 white, with brownish streaks. 



The COMMON AMERICAN GULL, L. zonorhyncus, (Gr. zone or 

 ring-billed,) has a mantle of bluish gray ; the head, tail, and 

 under parts, white ; the outer quills are black, tipped with white. 

 In the quills, however, the plumage changes with the age and 

 season. It is popularly called the BROWN WINTER GULL, a name 

 referring to the plumage of the young, rather than of the adult. 

 The ring on the bill is not always found. The length of this spe- 

 cies is nineteen inches. It is allied to the L. canus, (Lat. gray,) 

 or Gray Gull, of Europe, breeds from Maine northwardly, and 



