109 



shells, and the impression of the Cornu-Ammonis, indicate 

 its former less indurated state. 



The lower piece has some signs of incumbent strata hav- 

 ing been on the upper surface, in an obsolete impression, 

 and also some obscure crystals of carbonate of lime under- 

 neath. The fracture is in part largely conchoidal. With 

 some difficulty we may observe the woody stratification. It 

 is truly black. I have a piece where, the woody texture is 

 very evident, with small cubic pyrites on one side. With' 

 heat and water I decomposed a bit of it, so as very satis- 

 factorily to expose its woody structure. It comes very near 

 to the most indurated Bovey coal and surturbrand *, evi- 

 dently belonging to that division. 



* These also produce a brown powder. 



