hic thee) 
Read December 16, 1842. 
In a paper which I read before this society, in January of last year, I added fifty-seven 
new species to the genus Melania, and in a subsequent paper, several more were added. 
Recently Dr. E. Foreman, of Baltimore, very kindly sent to me all the specimens from his 
cabinet, of the family Melaniana and Peristomiana, with permission to describe what I 
might find new. There appeared to me to be twelve undescribed Melanie, four Anculose 
and two Paludine. These I have described in this paper. In my former memoir, I 
stated that Lamarck does not mention a single species of Me/ania as inhabiting the rivers 
of Europe, but since the publication of his great work, Dr. Philippi and some other zoo- 
logists, have described a few species from Italy and the astern parts of Europe. 
The genus Melania is greatly developed in the United States, while not a single spe- 
cies has been observed in Great Britain or the western part of the continent. When La- 
marck issued his 6th vol. in 1822, he was acquainted with only sixteen recent species, 
nearly all of which, he says, are exotic to Europe. Since that period our knowledge of 
this genus has greatly extended, and my catalogue now includes the names of two hun- 
dred and sixty-six species. This does not include the Anculosa, which Mr. Say very 
properly separated from the Melanie. My catalogue of these embraces thirty-three 
species. 
Of the two hundred and sixty-six* species of the genus Melanie, forty-fourt are in a 
fossil state, leaving two hundred and twenty-two recent. Of these sixty-one are exotic, and 
one hundred and sixty-one indigenous. Highty-eight of these are described in my pa- 
pers, including the present one, presented to this society. 
It is remarkable, that while such a vast development of this genus has taken place here, 
that as yet we have not observed a single species of the nearly allied genus Melanopsis in 
North America. It ranges in a variety of species from the Caucasus to the Alps. I 
have in my cabinet three supposed species from South America. One of these, the cre- 
nocarina of Moricand (a very interesting shell) will, I think, have to be removed to a new 
genus. The Brazilensis of the same author approximates more closely to Lamarck’s 
characteristics, but the callus is absent; and the same remark applies to the maculata, 
(nobis. }) 
* Of these there may be probably twelve or fifteen duplications. 
} For many years I have believed that many of Lamarck’s fossil Melanie belonged to other genera, and I find that M, 
Deshayes, in his notes to the new edition of Lamarck, mentions six ag certainly not Melanie. 
{ Having inadvertently in my former papers duplicated some names, I propose the following changes, Melania plica.. 
tula to M. Deshayesiana, that name being preoccupied by Deshayes. Melania plicata, to M. Menkiana, that name being 
preoccupied by Dr. Menke. Melania exarata, to M. arata, that name being preoccupied by Dr. Menke. Planorbis lens 
to P. Brogniartiana, that name being preoccupied by M. A, Brogniart, 
