MY A. 105 



This is not an uncommon shell in many parts of 

 Europe; but it was first described and figured, as 

 English, by Lister, and is a frequent inhabitant of 

 the Thames, and other rapid rivers. It is used, like 

 the preceding species, to hold colours, and from that 

 circumstance, has received the name of Painters Gaper. 



OVAL GAPER. 

 PI. 19./. 5. Mr. Sowerby. 



27. Mya ovata. M. testa ovata, antrorsum angustata. Linn. Trans. 8. 



p. 39. 

 Shell oval, narrow before. 

 List. Anim. Angl. App. f. 6. Donov. Brit. Shells, 1. 101. (M. depressa.) 



and t. 122. Mont. Test. Brit. p. 34. and p. 563. Linn. Trans. 8. 



p. 39. 



This is a thick shell, narrower than the M. JBatava, 

 but broader than the M. Pictorum. It is covered with 

 a green epidermis, which varies to a dark brown, and 

 is striated concentrically; there are, in many speci- 

 mens, obsolete rays running from the hinge to the mar- 

 gin. The hinge, like that of the two preceding species, 

 has a large crenated tooth, besides a long lateral one, 

 in one valve, and two lateral teeth in the other. The 

 difference between these three species of shells, about 

 which there have been so many contradictory opinions, 

 can in no way be so clearly established as by figures ; 

 we have therefore endeavoured to exhibit good speci- 

 mens of each, that their respective peculiarities may be 

 ' readily distinguished. 



The M. ovata inhabits the fresh waters of different 

 parts of Europe, and is found in England, in the rivers 

 Froome and Avon, in Somersetshire, and in the New 

 River, near London. 



