106 OF F O S S I L - S H E L LS, &c. 



i !. A finglc valve of the fmall t'elllna with deep furrows, and a 

 crenated margin (s). From the clay-bank above the bridge at 

 Simenburn, 



12. The laminated lel/ina-of a longer fhapc (t). From the fame 

 bank, in a bed of iron-fhiver. I met with many fair fpecimens 

 of it at different times, after great floods and intenfe frofcs ; the 

 fmalleft an inch long. 



13. The fmall laminated tellina of a more dcpreffed fliape. In. 

 the fame ftone with the* <?a//-mell, No. ?, and of the fame co- 

 lour. 



Single valves of the fea-mufcle are not unfrequcnt in iron-fto'ie 

 on the more of the brook at Go/ton. There are two of them in the 

 lafl mentioned ftone. 



We have {ingle valves of the great, round, convex Oftrta> the 

 Oftraclte of authors (u), plentifully in ftone on moft of the fhores 

 of our alpine brooks, and in many of the limeftone-quarries. 

 There are groups of them in large fingle maffes of limeftone 

 in the ftreamlet on the eaft fide of Simonburn-ca.ft.le. They are 

 common in limeftone quarries about Stamfordham ; in the large 

 quarry at Newton on the moor, near Alnivick ; in the quarry at 

 Blakela-w, on Uroad-pool-Common, near Simonburn ahd in another 

 large one on Wark-common, near Linacres, in .Tynedale. In the 



(s) Area flaftea) tefla fubrhomboidea obfolete decuflatim ftriata, natibus recurvis, mar- 

 gine crenato. Linn. Syft. Nat. p. 694. n. 143. FofT. Haat. p. 42. pi. 8. fig. 106. 



(i) Lift. Ang. p. 19. 



() Oftracites maximus couglobatus. Lh. Lith. Brit. n. 471. 



rugofus maximus. lift. Angl. p. 236. 



Plot's Oxfordfh. tab. 4. fig. 19. Charlet. Foff. p. 31. n. 18. 



laft 



