548 
PROCEEDINGS OF THE ACADEMY OF 
mere pierre-garin," BufFon and French authors. “ Gemeine, oder Rothfiissiger 
Meerschwalbe,” Bechstein, Meyer and German authors. “Wilson's Tern," 
Bonaparte, and most later American authors. 
Habitat . — Sea Coasts of Europe, part of Asia and America, ascending rivers 
and bays to a considerable distance. 
This species has been so long known that any description of its characters, 
or changes of plumage are unnecessary. Temminck says that the adults in 
winter do not lose the black of the crown, “ elle est seulement plus terne." If 
this be so, the species forms an exception to the general rule among Terns, 
that at this season the front becomes nearly white, the crown variegated with 
black and white, or the black still further reduced to a circumocular fascia. 
Comparisons of this species with S. Forsteri and macroura , its most intimate 
allies, will be found under the head of the former. 
The common Terns of Europe and America were considered identical by all 
writers up to the year 1838. At that date they were separated by Bonaparte ; 
and American authors, with the exception of Audubon, have generally followed 
his example. Iam little pleased to be obliged to refer to a European species, 
an American bird which has been judged distinct by high authority, but such 
a procedure seems unavoidable in the present instance. I am not aware that 
any distinctive characters have ever been assigned to our bird. Bonaparte, in 
instituting the species, gives no description, as, indeed, is the case with several 
other species founded in the same work, with regard to which he appears to 
have relied, for means of separating them from their European allies, rather 
upon some theory of geographical distribution, than upon any discrepancies 
presented by the birds themselves. I have very carefully compared a series of 
skins from both continents, and neither in size, form or color, have I been able 
to detect the slightest differences ; and consequently, until some one is more 
fortunate than myself in detecting valid specific characters, 1 must refer the 
American bird to the old Linnsean S. hirundo . 
Below are offered the detailed measurements of five American and European 
birds, taken at random from a large series. It will be observed that in no re- 
spect do the dimensions of the birds from the two continents present greater 
differences than are found in the various examples from either. 
A. — S. hirundo ex Europd. 
Cat. No. 
Sex. 
Locality. 
Wing. 
Tail. 
Bill. 
Tarsus. 
Middle 
toe and 
claw. 
Outer 
feather. 
Depth 
of fork. 
Length. 
Height 
at base. 
9559 
$ 
Europe. 
10-30* 
5-70 
2-65 
1 38 
0-33 
0-81 
0-97 
24280 
Holland. 
9-80 
5-60 
2-60 
1-51 
1-31 
0-78 
0-90 
21680 , 
Hungary. 
10-80 
6-20 
2-70 
1-45 
0-36 
0-80 
0 90 
23444 
9 
u 
10-60 
5-90 
2 -.70 
1-45 
0-32 
0-84 
0-96 
23445 
& 
u 
10-80 
6-50 
3-00 
1-35 
0-31 
0-80 
0-90 
B. — S. hirundo ex America. 
Cat. No. 
Sex. 
Locality. 
Wing. 
Tail. 
Bill. 
Tarsus 
Middle 
toe and 
claw. 
Outer 
feather. 
Depth 
of fork. 
Length. 
Height 
at base. 
18224 
Labrador. 
11-00 
6-50 
3-10 
1-50 
0-32 
0-84 
0-98 
22287 
Massachus’tts 
10-40 
5-90 
3-02 
1-41 
0-31 
0-78 
0-93 
1149 
9 
Cape May ,N.J. 
10-60 
6-40 
2-85 
1-36 
0-31 
0-78 
0-93 
20811 
c? 
Hudson s Bay 
10-40 
5-90 
2-85 
1-50 
0-32 
0-78 
0-95 
12474 
& 
Utah. 
10-50 
6-00 
2-50 
1-51 
0-35 
0-80 
0-95 
* Inches and hundredths. 
[Dec. 
