OF FOSSIL-SHELL S, &c. 113 



in iron-Hone ; of which I have met with feme very curious, both 

 indigenous and exotic. 



1. An acorn, without the hufk, filled with iron-Hone, the focket 

 of the ftalk confpicuous, alfo the thicknefs of the me 11 by a 

 frafture ; the conic point, or fmall end, in its natural colour. 

 From Simonburn, above the bridge. 



2. The reticulaj: nerves, or mafhes, of a leaf, found between the 

 lamina of blue clay, Several yards below the furface, at the fame 

 place. 



3. Polypody. A fair impreffion of it in iron-ftone. From the 

 ixon-mine at Bebftde. 



The late curious Dr. Jabez Cay, of Neivcajlle Upon Tyne, had 

 feveral fine impreffions of this fern, and of the Filix florida, or 

 Ofmund Royal, from the coal-pits at Kcttton> and Neivbiggen, near 

 that town. They were in the nodules of iron-ftone, called Cats- 

 heads, by our minemen; Cat'fcamps, at Whitehavcn, in Cumber- 

 land ; Ball-mine, in Staffordjhire ; and Minera Ferri Pilzfonnis, by Dr. 

 Lifter. Not above one in iive or fix have ferns in them, which lie 

 in the middle. They fplit with a flight ftroke at the very place, 

 if expofed to the winter's rigour, and mew the vegetable linea- 

 ments in their utmoft beauty. He had alfo impreflions of ferns 

 in coal-flate from Brunton and -8<mtW/-colleries (gj. 



4. An American fern in relief. From ^^/kfc-ironmine. The 

 imprefllon beautiful in the iron-ftone (hj. 



(s) Lapis minerae ferri, pilaeformi fimilis, hi ctijus meditullb, unum vcl plura filids 

 folia reprefentantur. Ph. Tr. No. 277. 



(b) See Dr. Hill's Hift. of Foflils, plate 6th. 



VOL. I. Q^ Anothe-r, 



