MOLLUSCS 113 



which inspired the ancients to represent the animal as 

 sailing before the wind with these peculiar arms upraised 

 to catch a favourable breeze. The male, only about 

 one-tenth the size of his consort, is not more than an inch 

 in length. The male element is generated in a sac-like 

 development of one tentacle, which is cast off and adheres 

 to the mantle cavity of the female. The male at no time 

 develops a shell and the female is seen only at the surface 

 when incubating the eggs, retiring to the depths as soon 

 as family duties are concluded. 



H 



