186 A SODA-FELSPAR ROCK. 



that the ferric oxide is a pseudomorph after a carbonate. 



The interference of adjacent spherulites produce polygonal 

 sutures in which the ferric oxide is sometimes concen- 

 trated ; but it occurs also in the spherulites. 



No. 354. Similar to the last. 



Feriic oxide in radial streaks between the blades or 

 prisms of felspar, which form the radial portions of the 

 spherulites. 



No. 355. Similar to the above, but with the ferric oxide almost 

 wholly concentrated in the polygonal sutures formed by 

 the niutual interference of adjacent spherulites. 



No. 356. Adinole? interbanded with slates. Dinas Head. 

 Compact banded bluish grey rock with brown rusty spots. 

 U nder the microscope the structure of the main mass of 

 the rock is seen to be crypto-crystalline, but the nature 

 of the material cannot be determined. The brown rusty 

 spots are sometimes irregular, and sometimes of such 

 forms as would be yielded by rhombs. There can be no 

 doubt that they are pseudomorphs after a ferriferous 



carbonate. 



J. J. H. Teall. 



Postscript. — Since the above was written, Mr. Beringer 

 informs me that in Brooke & Miller's Mineralogy, an analysis of 

 Adinole from Lerbach in the Hartz by Schnedermann shows 10 

 per cent of soda. 



