90 NAUTILUS. 



distinctly separated by the circumstance of one be- 

 ing concamerate, the other not so. The inhabi- 

 tant of the Nautilus^ as the shape of the shell will 

 indicate, possesses the power of floating on the 

 surface of the sea, but is more frequently found 

 reversed, and bearing his boat upon his back. 

 Some species are attached, by their base, to the 

 submarine rocks, from whence they are broken off 

 by the violence of the waves, and cast in fragments 

 on the shore. No exemplification is given of the 

 division C, because all the shells which it contains 

 are either minute or fossil, neither of which come 

 within the design of a work merely elementary, 

 and confined to recent subjects. Fossil concho- 

 logy, though subject to the same arrangement, is 

 well worthy of a separate consideration. 



To vuuriXog^ a sailor^ this genus evidently owes 

 its appellation. 



