Rocks and Minerals of British Guiana. 47 



NO. DESCRIPTION. LOCALITY. 



231 Quartz crystals from drusy 



cavity ... ... Takutu river. 



232 Gneiss, with granite vein Waini river, cataraft. 

 233-235 „ ,. ,> Barama river. 

 236-237 „ „ ,. Cuyuni river. 



238 „ ,, H Mazaruni river. 



239-240 ,. H » Dowacaima cataract, Barama 



river. 



241 u ,1 » Rewa river. 



242-245 „ ,, ,1 Upper Essequebo riv«r. 



246-251 „ I. ,, Quitaro river. 



252-253 „ ,. ., Rewa river. 



254-255 H with garnets Quitaro river. 



256-258 „ ,, ... Upper Essequebo river. 



259 1, H ... Barama river. 



260-263 •> » ••• Upper Essequebo river. 



264 ., 1, ... Rewa river. 



265 n » ••• New river. Corentyne. 

 266-271 „ I. ... Above King Fred. Wm. IV. 



cataraft, Corentyne river. 

 272 11 „ ... Curuni river, Corentyne 



river. 

 Demerara river. 

 Quitaro river. 



Near Suwaraowra river, Ta- 

 kutu savannah. 

 277-278 Decomposing gneiss ... Warrerie, Cuyuni river. 



279 ,, ... Carabung. 



280 Quartzose rock in gneiss Upper Essequebo river. 



281 Pitchstone ,, ... ,, 

 282-283 Gneiss with garnets ... ,, 



IV.— GRANITE AND GRANITIC ROCKS. 



284 Partially decomposed quartz- 



porphyry 



285 ,, ,, ,, ... Siparuni river. 



286 ,, ,, ,, ... Takutu, Siparuni river. 



-S7 ,, ,, ,, ... Itabru mountain, Bcrbicc river. 



