BIRDS OF PENNSYLVANIA. 19 



and feet black. Length 21^ inches; extent of wings 51 inches." Baird's Birds of 

 North America. 



Habitat. Nearly cosmopolitan ; in North America breeding southward to Vir- 

 ginia, Lake Michigan, Texas, Nevada, California. 



The Caspian Tern has been observed in but few localities in this state. 

 Hon. J. J. Libhart, in his ornithological report, published in the history 

 of Lancaster county, Pa., records the capture of two of these birds <c on 

 the Susquehanna at Marietta, September 21, 1847." About three 

 years ago Mr. Joseph Krider, of Philadelphia, had in his possession an 

 adult Caspian Tern, which a customer had brought to him to be 

 mounted. This bird was said to have been shot in Delaware county, 

 near Chester city. Mr. George B. Sennett has in his collection one or 

 two specimens of this species, taken at Erie bay, where nearly every 

 fall, in September and October, a few of these birds are seen. 



Sterna maxima BODD. 



Royal Tern. 



DESCRIPTION. 



This bird ranks next in size to the Caspian Tern. Bill about as long but much 

 more slender than bill of Caspian Tern ; tail conspicuously forked. 



Adult. Front, top and back of head glossy-black (some specimens have front of 

 head white) ; back and wings pale bluish-gray ; rump and upper tail coverts white ; 

 tail nearly white ; under parts white ; bill deep reddish-yellow ; tarsi black ; iris 

 brown. Length about 20 inches ; extent about 43 inches. 



Habitat. Tropical America and warmer parts of North America, northward to 

 Massachuse'tts, the great lakes and California. West coast of Africa, north to Tan- 

 giers. 



The Royal Tern, which breeds in great colonies along the Atlantic 

 coast, from Virginia southward, is a very rare and irregular visitor in 

 this state. Henry B. Graves records the capture of a specimen in Berks 

 county, in September, 1879. Dr. John W. Detwiller, of Bethlehem, Pa., 

 has also observed this beautiful Tern as a straggler in our state. I have 

 never seen this bird in Pennsylvania. 



Sterna forsteri NUTT. 



Forster's Tern. 



DESCRIPTION. 



" Adult. Upper part and sides of the head, to a line just below the eye, and hind 

 neck black ; back and wings bluish-gray ; primaries grayish-white on the outer 

 webs and dusky-gray on the inner next the shaft, and over the entire web at the 

 end, darker on the inner margin ; the remaining portion of inner webs white ; tail 

 bluish-gray, except the outer web of the outer tail feather which is white ; the inner 

 web of this feather blackish-gray for about two inches from the end ; rump white 

 with a slight tinge of pale bluish-gray ; sides of head, throat and entire under surface 

 white ; in the dried specimens bill is orange-yellow at the base, black near the end, 

 with the tip pale yellow; legs and feet scarlet. Length about 15 inches ; extent 

 about 30 inches." Baird's Birds of N. A. 



