1/2 



MytUusAnatinus. Don, Br. Shells, iv. t. 113. 

 Piilt. Cat. Dor/ct. p. 38. 



M. with a thin, femi pellucid, oval fliell, very like the 

 AL Cygneus, but ufually of a greener colour, lefs convex, 

 and the margin at the hinge more prominent, rifing into 

 a fort of angulated wing. Length two inches ; breadth 

 three and a half. 



This fpecies inhabits rivers, and other frefli -waters ; is 

 very plentiful, and frequently found where the M. Cygneus 

 is not. 



13. 

 AvoNENSis. Mufculus anguftior, fub-fufcus, pauIo crafTior, Lifter Conch. 



t. 154. f. 9? 



M. with a fub-oval Oiell, of an olivaceous-brown colour, 

 with concentric wrinkles: fize of the M. Anatinus, but 

 broader in proportion to its length, and not fo produced 

 at the hinge; the poflerior fide generally more obtufe, 

 and rounded; the front margin nearly ftrait, or frequently 

 fub-arcuated, particularly towards the fmaller end. 



In thefe particulars it feems to differ efTentially from 

 either the M. Cygneus or Anatinus, and is much Ids like 

 either, than thofe (hells are to each other. 



This fhell we found in great abundance in the river 

 Avon, about Lackham, in WiUJhire, where it is much more 

 plentiful than the Anatinus. 



Poflibly 



