BRITISH FOSSILS. 



3 



the plate, which fully corroborated the accuracy of Professor Agassiz's 

 conclusion, founded upon the isolated scales submitted to his ex- 

 amination. Although the species is recorded in the " Poissons 

 Fossiles,'' the description of it never appeared, in consequence of the 

 abrupt termination of that work. The great rarity of tolerably 

 perfect specimens from the shale-beds of our coal-measures, and the 

 value of well-marked species in considering the relations of these 

 beds in one district with those in others, render it desirable to record 

 a correct figure and description of this species, although it is not a 

 subject of novelty. 



Localities. — Silver dale, near Newcastle-under-Lyne, in a fine, com- 

 pact, black shale ; highly fissile, with a slightly conchoidal fracture. 

 Also in Lancashire and Yorkshire, and in some of the Scotch and 

 Irish coal-fields. 



Explanation of Plate. 



Fig. 1. Palaeoniscus Egertoni, natural size. 

 Fig. 2. Same, magnified twice. 

 Fig. 3. Scale, magnified ten times. 



P. DE M. Grey Egerton. 



