91 



PLATE XLVI. 



Spiropteris. 



SCHIMPER. 



Another beautiful specimen of circinate vernation, this 

 time probably in a Pecopterid fern. 



The drawing is by Prior, but no further information 

 beyond the fact that the specimen comes from the 

 Bensham seam horizon, at Jarrow Colliery, is to be 

 found respecting it. 



