VENUS. 59 



appearance from the species arranged under the 

 other sections, and indeed approach nearer to 

 the form of a Donax. The area is generally large, 

 lanceolate, distinct, very often coloured differently 

 from the disk. The areola is smaller, cordate, de- 

 pressed, and gives a peculiar character to the mar- 

 ginal outline of the valves. 



In the orbicular division a heart-shaped lunule 

 is distinctly marked on the areola, and is often pro- 

 minent; the area is usually compressed. 



The spines of V. Dione can scarcely be alleged 

 as an exception to the remark made on Cardium 

 echinatum, that in all other shells the suture of the 

 spines is placed on the side furthest from the apex ; 

 for in this muricated Venus the spines are evidently 

 formed by an extension of the transverse plaits at 

 an angle having its base towards the beaks, and 

 therefore necessarily open on the inner side. 



To the sea-born Goddess, of the ancient mytho- 

 logy, Linnaeus has dedicated the present genus, 

 selected from the produce of her native shores. 



