the Shells of Maine. 309 



As to the species of shells enumerated in this catalogue, 

 most of them are satisfactorily identified ; but in respect to 

 some, there is still much uncertainty. This is owing, in part, 

 to a want of the necessary books and plates, and partly to a 

 want of European shells for comparison. It becomes more 

 and more known, every year, that many of our species are 

 identical with those of northern Europe, and it is reasonable 

 to conclude that more extended observation will detect many 

 more coincidences : — exchanges are, therefore, solicited with 

 European naturalists, interested in this subject. 



In citing authorities it will be noticed that I have dropped 

 Professor Adams's name, in nineteen of the species which 

 were described under his name in connection with mine, in 

 Vol. iv., No. 1, of this Journal. In justice to him and to my- 

 self, this correction should be made, which accords with the 

 original paper, but which was overlooked by the publishers. 

 I, however, most cheerfully acknowledge my indebtedness to 

 Professor Adams for the assistance he afforded me in prepar- 

 ing that article for the press. In respect to the numerous 

 errors to be found in it, I will take this opportunity to remark, 

 that they were partly derived from precipitancy and want of 

 care in the original manuscript, and partly from errors of the 

 press, neither Mr. Adams nor myself having had proof sheets 

 in season to make the necessary corrections. However much 

 disgrace should attach to me for those mortifying blunders, 

 none can be laid to the charge of professor Adams, as it was 

 all re-written by myself, and several of the species were never 

 seen by him. 



In compiling this catalogue, I have the pleasure to acknowl- 

 edge my indebtedness to Dr. Gould's " Report on the Inver- 

 tebrata of Massachusetts," as well as to many personal favors 

 from that gentleman, pertaining to the same subject. I have, 

 also, derived much information from the papers of Mr. Cou- 

 thouy and Professor Adams. In my explorations I have 

 received much valuable assistance from my friend Captain 

 Walden, of the United States Revenue Cutter, Morris, — who 

 by his zeal in dredging in deep water, and exploring along the 



