ART. IIL—DESCRIPTIONS OF NEW SPECIES OF MOL- 
LUSCA AND SHELLS, AND REMARKS ON SEVERAL 
POLYPI FOUND IN MASSACHUSETTS BAY. By Joszru 
P. Covrnouv. Read January 17, 1838. 
In offering the following paper, I would state, in the 
first place, that nothing is herein described which has 
not fallen under my own personal observation. With 
regard to those which I have considered as new species, 
it may prove, hereafter, that some which I have re- 
garded as such, have already been described by English 
naturalists as inhabiting the coasts of the British Islands. 
After an examination, however, of the descriptions 
within my reach, and a comparison with the plates, 
where they existed, I have been wholly unable to satisfy 
myself of the positive identity of any one species. It 
has frequently occurred that a description has tallied 
very nearly with an object presumed to be new, when 
the accompanying plate has represented something 
widely different. On the other hand, figures have been 
found apparently corresponding to some of our species, 
where the description has been applicable only in one 
or two characters, which belonged in common to the 
whole genus. In some instances, it is true, the descrip- 
tions, so far as they extend, seem to coincide with those 
here given in most of the important specific distinctions ; 
but they omit much that is of equal importance, and, 
in justice to the describers, could hardly be supposed to 
have escaped their notice, if it really existed in their 
specimens. 3 | 
These remarks refer more especially to the shells 
