MYA. Ill 



ROUNDISH GAPER. 



37. Mya suborbicularis. M. testa suborbiculari, valvules altcrius dente 

 primario solitario, alterius duplicato, dentibus lateralibus lamellatis. 

 Linn. Trans. 8. p. 41. 



Shell roundish, a single primary tooth in one valve, a double one in the 

 other, lateral teeth laminated. 



Mont. Test. Brit. p. 39. item. Suppl. pi. 26. f. 6. 



This is a yellowish-white shell, frequently covered 

 with a brown epidermis, and faintly striated trans- 

 versely ; the inside glossy white. 



Mr. Montagu, to whom we are indebted for the know- 

 ledge of this species, discovered it at Plymouth, in 

 hard lime-stone. He adds, that it is sometimes dredged 

 up, free of any extraneous substance, in Salcomb Bay, 

 Devonshire. It very strongly resembles the Tellina 

 cornea, but is not a fresh- water shell. 



VARIABLE GAPER. 



38. Mya variabilis. M. testa subrhombea, gibbosa, umbonibus longitu- 

 dinaliter corrugatis, cardinis dentibus duobus, apice divergentibus, 

 foveis linearibus invicem insertis. Linn. Trans. 10. p. 327. t. 24. 

 f. 4, 5, 6, 7. 



Shell somewhat rhombic, gibbous, umbones longitudinally wrinkled; 

 hinge with two teeth diverging at the apex, and inserted into corre- 

 sponding linear cavities. 



This is one of the seven new species of 2 r estacea 9 

 described and figured by Dr. Maton, in the tenth 

 volume of the Jjinnaean Transactions. It is striated 

 transversely, and the longitudinal wrinkles disappear 

 towards the middle of the shell. The outside is brown; 

 the inside pearly, and bluish. The margin is some- 

 what angular before, and forms a straight line at the 

 hinge. The shell is about an inch long, and rather 



