62 CONCHOLOGY. 



sated striag; hinge completely straight, with two parallel 

 ribs at each end, the terminal teeth longer and more oblique 

 than the others ; exterior chestnut colour, interior white, 

 tinged with violet. 



2. Area. The Ark. Thirty-seven species. 



This genus is easily known by its resemblance to the 

 hull of a ship; the hinge is peculiar, being composed of 

 numerous sharp teeth alternately inserted between each 

 other. The Area of Linnaeus was divided by Lamarck into 

 the four genera that compose this family, each possessing a 

 strong distinctive character. All the shells of this family 

 are found in the sea at a little distance from the shore ; they 

 are covered with a dark greenish lamellar or velvet-like epi- 

 dermis, frequently ending in a deep fringe at the margin. 



Shell a little varied in form, but most generally elongated, 

 and more or less oblique at the posterior extremity ; some- 

 times very inequilateral ; summits more or less distant, and 

 a little recurved forward ; hinge anomalous, straight, or a 

 little curved ; long, and formed by a line of short vertical 

 teeth decreasing from the extremities to the centre ; liga- 

 ment exterior, broad ; sometimes the margin is crenated. 



