282 LONG-WINGED SWIMMERS — LONGIPENNES. 



grayish ; throat and forcneck uniform pale grayi.sh ; remaining lower parts, including the chin, 

 immaculate white. Bill, legs, and feet dull orange, the former with the tip blackish. 



Total length, about 21.50 inches ; extent, 51.00 ; wing, 15.00-17.40; tail, 5.30-0.75, depth of 

 its forking, .75-1.60 ; culmen, 2.48-3.10; depth of bill through base, .75-. 95 ; tarsus, 1.60-1.95 ; 

 middle toe, 1.15-1.40. 



The difference in size between examples of this species from North America and those from 

 Europe seems scarcely suthcient to warrant the recognition of a var. imiwrator. We have e.xam- 

 ined fourteen adult examples ; but of these only two were European, one being from Australia, the 

 others from various parts of North America, including the coast of California. The smallest of 

 this series is from Denmark, the wing of which measures only 15.00 inches, the culmen 2.48 ; but 

 a Californian specimen is scarcely larger, measuring only 15.15 and 2.50 respectively. The bill is 

 narrower in the latter specimen than in any other, measuring only .75 of an inch deep at the base, 

 instead of from .80 to .95. The largest specimen is one from Western Australia, which measures : 

 Wing, 17.00 inches ; tail, 6.50 ; culmen, 3.10 ; depth of bill, .90; tarsus, 1.75 ; middle toe, 1.30. 

 A Canadian specimen (No. 70316, 9, Detroit River, near Sandwich, Ontario, May 2) is scarcely 

 smaller, however, while the wing is actually longer, the measurements, as above, being 17.40, 6.05, 

 2.65, .86, 1.60, 1.22 inches. There are two American specimens in the collection which are decidedly 

 smaller than an adult male from Europe, one being the example from California, noted above, the 

 other from Wapitugan, Labrador. The latter measures 16.00, 6.00, 2.55, .80, 1.65, 1.15 inches ; the 

 European specimen in question being 16.00, 6.25, 2.75, .85, 1.65, 1.20. It is therefore evident that 

 while we may perhaps concede to the American birds of this species a larger average size, the dif- 

 ference is not sufficiently constant to warrant the formal recognition of a var. imj^erator based upon 

 difference of size alone. 



The Caspian Tern is somewhat cosmopolitan in its distribntion. It is of irregular 

 and comparatively limited occurrence, so far as we kno\v, in North America. Mr. Law- 

 rence has received specimens that had been procured on the southern coast of Long 

 Island. Dr. Turnbull mentions the taking of examples on the coast of New Jersey. 

 Mr. Boardman informs me that individuals have been occasionally taken in the Bay 

 of Fundy. Mr. William Brewster met Avith a flock at Ipswich, Mass., SejDt. 15, 1871, 

 one of which was secured. There were about half a dozen others flying about at the 

 time. Mr. Sennett saw this Tern on the coast of Texas, and Dr. Merrill found it 

 breeding on Padre Island, near Fort Brown. It has been found by Mr. B. F. Goss 

 breeding on islands in Lake IMichigan. 



Professor Kumlien, to whom this species was once familiar, informs me that he 

 has occasionally seen a large Tern in Lake Koskonong, Wis., which he is very con- 

 fident can be none other than this bird. He has seen it near enough to know that it 

 is a Tern, but has never been so fortunate as to secure one. He has met with it in 

 May and in June; but has never noticed more than three at a time, and generally 

 not more than one. 



Messrs. Ridgway and Henshaw found this species breeding on Cobb's Island, Va., 

 in the summers of 1879 and 1880. Late in July Mr. Henshaw procured one pair 

 with their downy young, and others were positively identified ; and there may have 

 been still other individuals among the large Terns seen at too great a distance to 

 be identified as not being the rer/ia. These two Terns are not distinguished by the 

 residents, both species being confounded under the local name of " Gannet-Strikers," 

 or "Gannets." The Caspian Tern is supposed to breed in considerable numbers on 

 certain islands in the vicinity of Cobb's. 



Mr. Kidgway now regards it as probable tliat the large red-billed Terns which he 

 saw at the Humboldt Marshes in September, 18G7, at Washoe Lake in May, 1868, and 

 at Great Salt Lake in June and July, 1869, were of this species, and not ,S^. maxima, 

 as he had sujjposed (" Ornithology of the Fortieth Parallel," p. 639). 



