SOLEN. 
557 
end of the shell, and its extremity terminating in a 
point, the animal is said to cut a hole in the sand, 
and afterwards to make it assume the form of a hook, 
so that it takes a firmer hold, and obliges the shell 
to descend. In this manner the little workman 
operates, till by repeated efforts the shell totally dis- 
appears. When the animal has occasion to return 
to the surface in search of food, the other shape be- 
comes of use, and the end of the instrument now 
assumes the form of a knob instead of a point. 
With this it presses firmly against the bottom of 
the hole; and the effect of this muscular effort is to 
push the shell in a contrary direction, so that by 
repeating the same the animal at length arrives 
at the top. Awkward as these shell-fish seem, they 
contrive to move in this manner with great dex- 
terity. 
