Class VI. MYA. GAPER. 167 



Discovered by Mr. Montagu in hard lime- 

 stone at Plymouth. 



■:■;..■..-• :; Monl. Test. Br. Sup. 20. ' . 15. DECUS- 



SATA. 



* M. with a white ovate shell, with irregular 

 concentric ridges decussated by regular longi- 

 tudinal sftics, which form tubercles at the an- 

 terior end ; margin waved ; length half an inch, 

 breadth rather more. 



IVith of Forth ; rare, 



Mont. Test. Br. Sup. 2\. i6. purpu- 



rea. 



* M. shell slightly wrinkled transversely, whit- 

 ish, with a purple tinge near the beak ; minute. 



Taken amongst coralline in deep water ; De- 

 vonshire coast. 



Mont. Test. Br. Sup. 22. ih. \Q6. I?, ferru- 



GINOSA. 



* M, with a white subovate shell, moderately 

 convex with obsolete wrinkles j beak obtuse, 

 near one end front margin nearly strait; 

 breadth half an inch, length a quarter of an 

 inch. 



Found on Belton sand near Dunbar in Scot- 

 land. 



