485 



think the Do6lor has erred : the latter author has well 

 defined this fhell No. 385, where he fays " Ancylus tejla 

 inembranacea mucrone verticis fubcentrali, apertura ob- 

 lov.ga. It differs from the Jluviatilis in being much 

 longer in proportion to its breadth, in being much more 

 comprefTed, and in the vertex being m.uch fmaller, 

 placed more central, and always turning a little to one 

 fide. It is not near fo plentiful a fpecies as the other, 

 never attaches itfelf to ftones, but is always found on 

 plants under water, efpecially the Scirpus lacujiris and 

 other rufhes, as well as the common reed, Typha latifo- 

 lia, ftalks of the common flag, and Irus pfeudacorus. Is 

 not uncommon upon thefe plants in the ditches of Deal 

 marflies, in Kent, particularly on the laft, as we are in- 

 formed by Mr. Boys ; and Lightfoot fpeaks of its 

 being found on the fame plant, in waters near Beacons- 

 Jield, in Buckinghamjkire. Muller fays " Foliis Nym- 

 ph(ECE, Potamogetonis, (3 Stratiotis adhccret." 



We have them tolerably plentiful in a fifli-pond at 

 Lackham in Wilfjhire ; and in the river Avon, on the 

 flalks of the Yellozv water-lily ; but is ravely, if ever, 

 found in rapid waters, in v.diich the Jluviatilis feems 

 moll to delight. 



7. 

 Patella antiquata. Lin. Syft. p. 1259.— Gmel. Syfl. p. 3709 ? Axti^uata. 

 Martini Conch, i. t. 12. f. 111. 112. Tab. 13. f. 9, 



Lijier Conch, t. 544. f.31. 



PatelU 



