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 Abgonaxjt. 



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 



