1905 - 1906 .] 
THE CARNMONEY CHALCEDONY: 
Its Occurrence and Origin. 
(With a General Note on the Formation of “Secondary’ 
Siliceous Minerals in Volcanic Lavas). 
By JAMES STRACHAN. 
Being an Appendix (No. 8 of Vol. II.) to the Proceedings of the 
Belfast Naturalists' Field Club, for 1905-6. 
H 
