171 



M. with a thin, fragile, femi-pellucid, oval fhell, wrin- 

 kled concentrically, and covered with an olivaceous-green 

 epidermis : umbo very fmall, placed near to one end. In- 

 fide glofTy pearlaceous-white. Length rather more than 

 two inches and a half; breadth near fix inches. 



This is the largefl; of the Britijh frefh-water fliells. In- 

 habits dull, deepvrivers ; but rarely found fo large as in 

 ponds and flagnant waters. 



It bears great affinity to the M. Anatiniis, and has, by 

 fome, been confidered as the fame : the material diftinftion 

 is, that this is vaftly fuperior in fize, more convex, broader 

 in proportion to its length, and does not rife fo high at 

 the hinge ; though both (hells are compreffed at that part. 



It mufl however be allowed, that the fpecific charafters 

 of didinflion are not flrong: and much is to be depended 

 on the circumftance, of their being frequently found in 

 feparate places : and that this is not near fo common. 



13 



Mytilus Anatinus. Lin. Syji. p. 115S. — Gruel. Syfi. p.3S55.16. Anatinus. 

 Ckin. Conch, viii, t. 86. f. 763. 

 Lijler Ccnch. t.l53.f.8.— /</. Aji^J. t,2.f.29. 

 Schroet FlvJJconch t. 1. f 2. 3. 

 Mullcr verm. p. 207. No. 393. 

 Pctiv. Gaz. t. 93. f. 8. 9. 

 Br. Z)oI. t.6S. (.79.— Turt. Lin. i\/'.p.29S. 

 Da Cojta p. 213. t. 15. f. 2. 



Z 2 Mytilus 



