Rocks and Minerals of British Guiana. 45 



NO. DESCRIPTION. 



146 Porphyritic greenstone 

 147 



148 Coarse diorite ... 

 149-150 



151 Porphyritic greenstone 



152 Amygdaloidal ,, 



153 Botryoidal haematite in cavi- 



ties, in greenstone 



154 Natrolite from cavities in 



greenstone ... 



LOCALITY. 



Pacutout catara6t,Potaro river. 

 Near Carabung mouth, Maza- 



runi river. 

 Above Turisi cataraft, Maza- 



runi river. 

 Near Teboco cataraft, Maza- 



runi river. 

 Curuni river, Corentyne river. 

 Above Paumbo island, Esse- 



quebo river. 



Roraima mountain. 



Curua rapid, Rupununi river. 



III.— MET AMORPHIC FORMATIONS. 



Totohwow river, Carawaimen-. 



tow mountain. 

 Barama river. 

 Carabung river. 

 Cuyuni river. 

 Puruni river. 

 Curiebrong river. 

 Near Peaimah fall. 

 Barama river. 



Issano river, Mazaruni river. 

 Cuyuni river. 

 Barama river. 



Curuni river, Corentyne river. 

 Itaburro river, Upper Deme- 



rara river. 

 Mazaruni river. 

 Barama river. 

 Carawaimentow mountain. 

 Barama river. 

 Upper Essequebo river. 



