226 EXPLANATION OF TERMS. 



by permanent marks called specific cha- 

 racters. 



Striated. Marked with fine striae, or lines, 

 either hollow or raised; from stria, a 

 stripe. 



Sinus. A gutter, or curvature ; from sinus, a 

 curved line. 



Sinuous. Having a curvature. 



Subulate. Tapering, or pointed ; from subuk, 

 a pointed tool. 



Sagittate. Arrow-like ; from sagitta, an arrow. 



Siphon. A pipe through which liquids are con- 

 veyed. 



Sub. In composition means almost, or approach- 

 ing to. 



Setaceous. Bristle shaped; from seta, a bristle. 



Semi. Half. 



Sinistral. On the left hand ; from sinistra, the 

 left hand. 



Sides. The right side of a univalve is that op- 

 posite the right hand of the person looking 

 at it, when the shell is placed on its base 

 with the aperture in front : the left side 

 that opposite the left hand, the shell being 

 in the same position. 



Terrestrial. Belonging to the earth ; from terra, 

 earth. 



Testaceous. Composed of the materials which 

 form shells : from the Latin testa, a shell. 



Tentacula. The feelers of the mollusca; from 

 the Latin tento, I try. 



