170 MMiscellanies. 
The first persons who occupied themselves with the scientific ex- 
amination of this family, were Messrs. Barnes and Say ; the results 
of whose labors, especially those of the former, are contained in the 
pages of this Journal. Mr. Say still continues to devote his attention 
to the Uniones, as appears from the numbers of the American Con- 
chology, published at New Harmony. Dr. Hildreth, of Marietta, 
has also contributed his share towards the elucidation of the Naiades. 
But the papers of Mr. Isaac Lea, in the Transactions of the Ameri- 
can Philosophical Society, stand pre-eminent among all the labors of 
this kind, both for extent and nicety of discrimination. ‘This gentle- 
man has explored, in person, their localities, and has had the good 
fortune to receive, from time to time, the most abundant supplies of 
them from his friends, resident at the west; so that his cabinet, as 
all can testify who have examined it, illustrates the different species 
in a high degree of completeness,—containing individuals of all ages, 
and from distant localities, and those which exhibit, also, the various 
aceidents under which they are liable to occur. Nor have his ex- 
aminations been confined to the mere shells and dead animals: he has 
preserved the same individuals alive under his eye for months, and the 
observations he records concerning their habits and anatomy, are ex- 
tremely interesting and original. 
The number of species put forth by Mr. Lea, as new, is so great, 
as at first to excite the suspicion, that many of them must eventually 
prove mere varieties of one another, or of older species; but who- 
ever will carefully peruse his memoirs, and much more, examine his 
cabinet, will be satisfied that the grounds of his distinctions are at 
least as stable as those of the most distinguished writers upon these, 
conlessedly, most difficult genera in which, says Lamarck, “les 
espeéces se nuancent et se is ae les unes dans les autres, dans le 
cours de leurs variations.’ 
We shall now glance at the most important contents of Mr. Lea’s 
several papers; commencing with his view of the genus Unio, so far 
as our own country is concerned. ‘The first column exhibits the no- 
menclature of the species as proposed by him for general adoption, the 
second the species described by other writers which are ether the 
same or varieties, and consequentiy Tees 
: radiata, Lam. 
1. U. radiatus, Gmelin. : virginiana, Lam. 
3. radiatus, Barnes. 
