The paper sailor, Argonauta argo, 

 in its natural position when floating 

 on the surface of the sea. (Tryon.) 



pared with that of the Nautilus., nor with the pen or internal support 

 of the squid, for it is attached to the animal by no muscles, and is only 

 kept in position hy the broad webs on the upper arms of the female 

 which alone possesses a shell, and its function is simply to protect the 

 eggs. The male is very much smaller than the female, and is exceed- 

 ingly rare. The female, when in natural 

 position, has the arms spread out and 

 hanging about the shell, four in front 

 and four behind, and the two broad arms 

 which support the shell are expanded and 

 closely embrace it. The siphon is turned 

 toward the ridged part of the shell, and 

 the animal progresses in a backward di- 

 rection by forcibly ejecting water through 

 this organ. It crawls on the bottom 

 of the sea with the shell on its back, like 

 a snail. The argonaut shells are found in all warm seas. 



The poets have given us many beautiful writings detailing the vices 

 and virtues of the lower forms of life, and among these the pearly 

 nautilus and the "paper sailor" have received a good share of the muse's 

 attention. But the poet, not writing as a conchologist, sometimes mixes 

 the relationships of these creatures, and we must not be misled, knowing 

 that poetical license sometimes takes liberties with scien- 

 tific facts. 



The Spirula is a mollusk whose shell is cast up on the 

 shore by thousands, but the animal of which is very rare. 

 The shell is less than an inch in diameter, is made in the 

 form of a loose spiral, and is divided into little chambers 

 connected by a siphuncle. The shell of this genus does 

 not contain the animal, as does the shell of the Nautilus, 

 but it is enveloped in two flaps of the mantle, at the 

 posterior part of the animal, and is concealed, with the 

 exception of a part of its edge, on each side. The body 

 of the animal is long and cylindrical, and the arms are 



Th^ shell is quite short, more nearly resembling those of the Nautilus 

 shown as if seen than tl)ose of the Q ctopu ^ or SC{U {^ The body ends in a 



disk, which is supposed to be a kind of sucker, by which 

 the animal can adhere to rocks, thus enabling it to freely 

 use its arms in obtaining food. It has been supposed by some 

 anatomists that the shells of the fossil Ammonites were attached to the 

 animal in a similar manner. If this can be shown to be true, these 



135 



through the 

 mantle. (Wood- 

 ward.) 



