148 THE ELEMENTS 



shell, when laid upon the aperture 

 or opening. In the genera of Pa- 

 tella and Haliotis, the back means 

 the upper convex surface. 



Dotted, punctured like a thimble. 



Dual, expressive of the number two. 



Duplicated, deeply divided as if bifid. 



Duplicature, a fold, any thing doubled. 



Duodecuple, consisting of twelve, 

 twelve fold. 



Echinated, bristled like a hedge-hog, 

 set with spines. 



Effuse, generally applied to where the 

 aperture is not whole behind, but 

 the lips are seperated by a gap so 

 that water poured in runs out at it. 



Elliptical, having the form of an ellip- 

 sis, oval. 



Elongated, lengthened, drawn out. 



Emarginate, to take away the margin 

 or edge of any thing; without a 

 margin. 



Ensiform, two-edged, sabre-shaped, 



