THE SHELL-FISH OF THE COAST. 15 
have been performed under full sail. The broadly- 
expanded, uplifted arms, which are seen on many 
of the older illustrations, and which were supposed 
to catch the gentle zephyrs of the purple sea, are 
now known to be closely appressed to the side of 
SHELL OF ARGONAUT. 
the shell, which they in truth secrete. Far, there- 
fore, from presenting the graceful outlines to which 
we have been accustomed, the Argonaut in swim- 
ming much more nearly calls forth the image of a 
retreating sneak. But the shell, considered apart 
from the animal, is perhaps the most beautiful and 
delicate that has been fashioned by nature. Owing 
to its great frailness it is but rarely found unin- 
jured, the free margins usually exhibiting nicks 
and cracks of greater or less extent. Hence the 
value attached to perfect specimens. For one such 
specimen of unusual size, formerly in the posses- 
sion of the Boston Society of Natural History, it is 
claimed that the purchase-money amounted to $500. 
The shell belongs exclusively to the female, and its 
