GLYCYMERIS. 



cular impression of the mantle are so similar and con- 

 fluent, that the shell might be said to have one muscular im- 

 pression running round its inside, except towards the hinge. 



Until Lamarck observed the distinctions, the shell' 

 which we have figured as the type of this Genus was ar- 

 ranged with the Myce under the name of M. Siliqua: but, 

 as he well observes, its hinge is not like that of the Myce^ 

 nor that of the Uniones, which were also called Myce: 

 having an external ligament, and being destitute of teeth. 

 The situation of the ligament and the want of teeth, dis- 

 tinguishes it also from Solen; to which, however, in our 

 opinion, it does not bear a very near resemblance : we 

 cannot at present offer a conjecture as to its proper situa- 

 tion in a Conchological System. Lamarck says, the shells 

 of this Genus are marine ; he describes two recent species 

 and one fossil from Grignon. 



