254 SPENCER FULLERTON BAIRD 
Uniones now are entirely barren, and some species have become nearly 
or quite extinct in the Cuyahoga River. Both fluviatile and terrestial 
univalves have also decreased with equal rapidity. The delicate 
Helix Sayii is no longer found in Northern Ohio so far as my observa- 
tion extends, and many other species that were once very common 
are now to be met with only accidentally. 
In a recent communication from J. Bartlett of Columbus, he 
has furnished me with many interesting facts that go to show that a 
similar change is taking place in other sections of our state. He and 
myself made extensive collections in the valley of the Scioto sixteen 
years since. Various species then existed there in profusion and the 
specimens were more perfect and beautiful than I could elsewhere 
obtain. He is now going over our old ground and he informs me that 
they have become as barren as ours at the North. In another genera- 
tion many of our finest species will cease to be known except in books 
and cabinets. 
The causes seem to be, Ist; The corruptions accumulating in 
canal and smaller streams from barnyards, roads, manufacturing 
establishments &c. 2d; The destruction by swine. Our woods are 
constantly ransacked by these animals and at low stages of water 
and when the water in our canals is let out they are searching every 
sand bar for testaceous animals. 
Very truly yours, 
J. P. Kirtrianp. 
From Thomas M. Brewer to Spencer F. Baird. 
Boston, Feb. 7, 1851. 
My pDEAR Balirp; 
And now a few words as to the bird from Labrador. In 
New York, Mr. Lawrence had prepared me for thinking it a new 
species, but upon my arrival at Philadelphia, I mentioned to Dr. 
Wilson and Mr. Cassin the brief description of a species resembling 
the Saxicola Oenanthe described in Beechey’s voyage; We took the 
volume, compared the bird by measurement with that description 
and Mr. Cassin expressed himself perfectly satisfied it was the same 
thing. He said nothing about any generic differences nor did there 
appear in his mind any doubt upon the subject. Of course, if I had 
