THE NAUTILUS. 49 



she arrives at maturity, and the membrane, being no longer 

 wanted, most probably decays. 



Such, then, is the conformation of this wondrous creature. 

 As regards the forming of her shell, she is conjectured, when 

 in embryo, to construct a simple hollow shell, the nucleus 

 of a spiral coil, from which she partly emerges ; and, in order 

 to fulfil her destination, she divides the empty portion of her 

 dwelling into compartments, between each of which she 

 forms a calcareous partition-wall. 



The natural position of a Nautilus is with the back of 

 her head and concavity of the hood against the chambered 

 portion of the shell ; the funnel resting on the outer con- 

 cave lip, the tentacles protruded over the side-margins of 

 the aperture, and the body retained witliin the shell by the 

 membrane and its horny girdle. Thus constructed, the 

 creature makes her way along the sandy bed of ocean with a 

 moderate degree of rapidity, carrjing her boat after the 

 manner of a snail ; and though in general remaining tranquil 

 in her watery haunts, she has undoubtedly the power of 

 rising and floating on the surface. 



Poets have sung concerning her sails and oars, that to 

 her belongs the power of unfolding the one at pleasure, and 

 of using the other with which to impel her fairy boat : — 



E 



