OBSERVATIONS. 



The elevated line of the posterior suhmargin and the re- 

 flected posterior edge are very characteristic, distinguish- 

 ing this species from all others, excepting the figure 2 of 

 the plate on Lutraria in the second volume of Mr. Sower- 

 by's excellent work on the '• Genera of Recent and Fossil 

 Shells." Our shell is much shorter on the posterior end 

 than liis figure, which he refers with doubt to the papyra- 

 cea of Lamarck ; a difference which, however, may be at- 

 tributable to an inequality of age, as it becomes more elon- 

 gated anteriorly in the older shell. Whether or not the 

 present species is the same as that of Lamarck we cannot 

 at present determine, but it is without doubt closely allied 

 to it. Still, however, it does not agree with the figure in 

 the Encycl. Meth. 257, fig. 2, a. b., quoted by Lamarck. 



The I'meata is not uncommon on the southern coasts^, 

 particularly on those of Georgia and East Florida, but we 

 have not yet found it so far north as Newjersey. 



REFERENCE TO THE PLATE. 



An outer and inner view are represented. 

 PLATE IX. E 



