200 



POPULAR CONCHOLOGY. 



the margin fringed all round, resembling a 

 double row of festoons. — 15 species, recent. 



The form of this shell somewhat resembles 

 that of the human ear, and it is from that 

 circumstance frequently called the Ear-shell; 

 one species, from its length, haying received 

 the name of the Ass's Ear. The outside is 

 generally rough, worn, or covered with marine 

 substances ; the inside presents the same ena- 

 melled appearance as mother-of-pearl, and ex- 

 hibits the most beautiful colours. The holes 

 with which the shell is perforated are for the 

 passage of the lobes of the animal's mantle, 

 and are made at regular intervals, as it in- 

 creases in size. It is observable, however, that 

 as each new one is formed the one nearest the 

 spire is closed up ; so that there are generally 

 the same number open at a time, and seldom 

 more than seven or eight. The annexed cut is 

 a representation of one of the species of this cu- 

 rious genus, with its living inhabitant, which, 

 notwithstanding its apparent size, can be co- 

 vered by the shell. In its state of rest, it is 

 able to adhere with such tenacity to the sub- 

 stance it is fixed upon as to be removed with 



