RHYNCHROPS NIGRA. 23 



with the Sooty Terns, but always places the nest in trees, and like the other species,ia 

 so tame that the eggs may be removed from beneath the bird witliout causing it to leave 

 the nest. The eggs arc deposited early in May. 



(jENUS IV. RIIYNCHOPS. THE SKDIMERS. 



Bi//, broad at base, much compressed lateral! y, with the lower mandible extending considerably beynna i/ppir. Leys and 

 winys, lony. 



Members of this genus are remarkable on account of the peculiarly c<jnstructed bill, the elongated under mandible of 

 which has numerous oblique ridges along its sides. Tail, short and forked. There is but one species within our limits. 



RHYNCHOPS NIGRA. 



Black Skimmer. 



Rhynchops niyra Linn., Syst. Nat., I, 1760, 2'28. 



DESCRIPTION. 



Sp. Cii. Form, robust. Size, large. Color. Adult. Above sooty-black, with tips of secondaries, forehead, outer 

 webs of tail feathers, and entire under parts, white. Bill, black, yellow at base, iris, brown, and feet, yellow. 



OBSERVATIONS. 



Known by the peculiar bill. Distributed, in summer, from New Jei-sey, southward. Rare further north. Winters 

 in Florida. 



DIMENSIONS. 



Average racasurement-s of specimens. Length, 17'5'2; stretch, 4r95; wing, 1 1'75; tail, 5'2.5; bill, 3-72; tarsus, |-35. 

 Longest specimen, '20'l(i; greatest extent of wing, 44'05; longest wing, 15'52; tail, 612, bill, 4'.52: tarsus, T.'jS. Shortest 

 specimen, <4-95; smallast extent of wing, 39'!j8; shortest, wing, 14'05; tail, 4'38; bill, 2'88; tarsus, 1-20. 



DESCRIPTION OF NESTS AND EGGS. 

 Eyys, placed on the ground in sandy places, two or three in number, oval in form, yellowish-while in color, sjjotted and 

 blotched rather coarsely with brown, umber, and lilac of varying shades. Dimensions fVom r35x r65 to T-litx 1-98. 



HABITS. 



One night, late in December, after a long and stormy A'oyage from the cold, frozen 

 North, I was leaning over the rail of a steamer which was lying at Fernandina, Florida, en- 

 joying the summer-like warmth of the air, and watching the play of the moonliglit on the 

 water, when I was almost startled bj' hearing a harsh note, sounding like the bark of a 

 young dog. Turning quickly in the direction of the sound, I saw several shadowy forms 

 moving swiftly along the surface of the water, but they quickly disappeared in the .sur- 

 rounding gloom, yet the singular note came to my ears several times from the distance. 

 What these mysterious birds were, I knew not at the time, but later, discovered that the note 

 I then heard, was produced by the Black Skimmers, and I found that the habit of flying by 

 night in order to feed, was regular; in fact, the species is almost wholly nocturnal in win- 

 tor. I have, however, frequently seen them on cloudy days, skimming along in the usu- 

 al way, with the elongated under mandible beneath the water. Tiiey generally move in 

 small companies and fly up rivers or creeks. During the day, they gather in large flocks 

 on sand-bars to rest, but are exceedingly wild and very difficult to approach. They breed 

 late, about June first in Florida, but not until the last of the month, further nortli. Tiie 

 handsomely marked eggs are deposited on the naked sand. 



(iENUSV. LARL'S. THE GULLS. 

 Gen. Cu. Bill, shorter than head, usually strDiuj, somewhat curved. Leys, long, toes webbed to tips, while the tail is ei- 

 ther rounded, square, or emaryinate. 



Members of this genus are usually large in size and light in color. AVe have eight species within our limits. 



LARUS GLAUCUS. 

 Glaucous GuU. 

 Larus glaucus Brun., Orn. Bor. ; 1764,44. 

 DESCRIPTION. 

 Sp. Ch. Form, robust. Size, very large. Color. Adult. Back and upper portion of wings, very light pearly-blue. 



