CATECHISM OF CONCHOLOGY. 61 



A. The shell is univalve, spiral, subdiaphanous, 

 or transparent, and brittle. The aperture is 

 contracted, semi-lunar (like a half-moon), or 

 roundish. To which description it is proper to 

 subjoin, that there is not the smallest columella 

 lip in this genus, and that the body uniformly 

 projects convexly into the circumference of the 

 aperture. The whorls are generally continuous. 



Q What does the generic appellation signify ? 



A. It is derived from a Greek word, signifying 

 a shell constructed with a spire or with circum- 

 volutions of the whorls. 



Q. Is not this kind of shell-fish eaten in foreign 

 countries ? 



A. Yes, they are esteemed as delicacies in the 

 Mediterranean. A large species were cultivated by 

 the Romans in beds, as Oysters are at the present 

 time; and they are supposed to have furnished the 

 Israelites with food during their rapid flight from 

 Egypt.* 



Q. Are all the Helices land shells ? 



A , They are found in very dissimilar situations : 

 a considerable number inhabit wet ditches, a few 



* Conchologist's Companion. 

 F 



