22 



Ferruginosa. Shell fub-ovate, moderately convex, and white, with ob- 

 Tab. 26. f. 2. folete wrinkles: m;w6o obtufe, placed neareft to (-ne end; 

 front margin nearly ftraight. Infide glofly w'nte ; hinge 

 furniflied with two proje6ting teeth, one of wliich is ereft, 

 the other turns inwards, and flopes downwards ; thefe teeth 

 are leparated by a large triangular notch that runs to the 

 umbo. Length rather more than a quarter of an inch ; 

 breadth nearly double its length. 



This new fpecies of Mya is ufually covered with a thick 

 tenaceous ferrugenous coatof argillacious earth, wliich muft 

 be removed to difcover the real colour of the fhell. It was 

 firft noticed by Mr. Laskey, and afterwards by Mr. H. 

 Boys, on Belton fand, near Dunbar, in Scotland, who 

 obligingly favoured us with fpecimens and remarks, by 

 which we are informed it is a rare fpecies. 



LIGULA. 



Animal an ASCIDIA. 



SHELL, bivalve : equivalve. 



Hinge with a broad tooth in each valve proje61:ing in- 

 ^vards, furniflied with a pit or cavity for the reception of the 

 conne(5ting cartilage ; in fome fpecies a minute ere<il tooth. 



It 



