Jan., 1909. Birds of Illinois and Wisconsin — Cory. 303 



eggs are 3 or 4, pale gray or buff white (sometimes faintly greenish), 

 marked and blotched with chocolate brown similar to forsteri, but 

 at times showing a more greenish tinge than those of that species. 

 They measure 1.82 X 1.30 inches. " Very abundant migrant. * * '" 

 A few still breed on small islands at the northern end of the Lake." 

 (Xelson.) "More common on Lake Michigan than forsteri and more 

 abundant here than in the interior of the state, preferring the gravelly 

 or sandy islands of the Lake and Green Bay for nesting places rather 

 than the smaller inland lakes." (Kumlien and Hollister, Birds of 

 Wisconsin, 1903, p. 13.) 



27. Sterna paradisaea Brunn. 

 Arctic Tern. 



Distr.: Northern hemisphere, breeding in North America from 

 Massachusetts northward to the Arctic regions, south in winter to 

 the middle Atlantic states and California. 



Adult in summer: Similar to the Common Tern, but differs in 

 having the tarsi shorter and the bill usually entirely red, not broadly 

 tipped with black. The white on the inner webs of the first and second 

 primaries extends considerably nearer to the tip of the feathers than 

 in 5. hirundo. 



Length, about 15.25 ; wing, 10.25; bill, 1.25 to 1.35 ; tarsus, about 

 .65 (less than .70). 



This species has not apparently been observed in Illinois. Kum- 

 lien and Hollister (Birds of Wisconsin, 1903, p. 13) state, " A somewhat 

 irregular migrant, at times fairly common and again quite the oppo- 

 site. We have taken it nesting in Green Bay, 1879; and in June, 1891, 

 procured a set of eggs (the parent shot on the nest ) at Lake Kosh- 

 konong. These nesting records are, however, to be considered ex- 

 ceptional. * * * * Less common in the fall than in the spring, less 

 often met inland in the fall than the two preceding, and not as abun- 

 dant as either at any time or place in the state." 



Subgenus STERNULA Boie. 



28. Sterna antillarum (Less.). 



Least Tern. 



Distr.: Ranges from Labrador to northern South America, and 

 in the interior west to Dakota and Mississippi Valley, breeding nearly 

 throughout its range. 



