EXPLANATION OF PLATE XXXIII. 



Datolite. 



Colebrook Mine, Dundas, Tasmania. 



Fig. 1. Clinograpliic drawing of ideal crystal. 



2. Plan of fig. 1. 



3. Clinographic drawing of natural crystal. 



4. Plan of fig. 3. 



5. Stereogram. 



Forms :—c (001). n (100) ; w (110) ; w, (Oil), ;" (013), .r (102) ; n (111), k 

 (ll.-,),/x ("lU), A (~113), £ (112), t (212), TT ("231). 



