OF CONCHOLOGY. 107 



Tellina Tenuis, to which it bears 

 some resemblance, but may be easily 

 distinguished from that shell, by the 

 right valve being covered with a fine, 

 regular, diagonal striae ; which is not 

 conspicuous without the assistance of 

 a lens, which makes it appear very 

 plain. Not uncommon on the coasts 

 of Northumberland, Dorsetshire, and 

 Devonshire. 



Linn. Trans, vol. viii. page 52. 



/ Cartilage, q q hinge. 



Fig. 4th! — MYT1LUS EDULIS. 

 Shell oblong, pointed at the beak, sides 

 much sloped ; anterior side a little 

 angulated ; smooth and radiated with 

 deep blue, or purple ; covered with 

 an umber-coloured epidermis. Inside, 

 round the margin, of a fine blue, which 

 grows gradually lighter towards the 

 centre ; cicatrix very distinct and 

 glossy ; beneath the beak are several 

 crenulations, which some have sup- 

 posed to be teeth. This is the most 



