21 



fragilis, the ocean snail, from the coast of Nantucket, pre- 

 sented by Mr. Greene. 



The operculum of the animal is modified into a vesicular appen- 

 dage, which serves to suspend it on the surface of the water. Ac- 

 cording to Dr. Coates of Philadelphia, who had an opportunity of 

 studying the animal, while crossing the ocean, the float has no 

 anatomical connexion with the animal. The membrane enclosing 

 the cells is secreted by the foot, which the animal throws back 

 upon the water, expanded to the utmost ; then by contracting the 

 edges it is formed into the shape of a hood, enclosing a globule of 

 air, which is applied to the float. ^Vhenthe foot is withdrawn, the 

 globule is found enclosed in its newly made envelope. Mr. B. 

 quoted several interesting facts from authors concerning the habits 

 and structure of this animal. 



On motion of Dr. Storer, it was Voted, That the President 

 of the Society be requested to make known to the Secretary 

 of the Navy, the past history and present condition of this 

 Society, to show what it has done for the advancement of 

 natural science and national honor, and to point out its 

 claims to national patronage ; and respectfully to petition 

 that a portion of all the specimens which may be received 

 from the Exploring Expedition may be set apart for the cabi- 

 net of this Society ; and that said petition be given to our 

 distinguished associate. Hon. Robert C. Winthrop, for pre- 

 sentation, and that he be requested to use his influence to 

 further the views of the Society in obtaining a part of said 

 specimens. 



On motion of Dr. Storer it was Voted, that the thanks of 

 the Society be presented to Mr. John Warren for his gentle- 

 manly conduct in throwing open his entire collection of 

 shells for the examination of a special committee ; and for 

 the very liberal manner in which he offered and urged upon 

 that committee the acceptance of all the species he pos- 

 sessed, not already belonging to the Society's cabinet, not 

 even withholding those upon which he placed the greatest 

 value. 



