Quart. Journ. Geol. Soc. Vol. LXVII, Pl. XXXVII. 





Fig. I- 





HE^ 5 *^ 



^w^H 



Ww 





m i 





x 20 



Fig. 2. 



x 20 

 W. i". Bouitan. Microp' Bemrose Ltd., Colio., Derby. 



ROCKS FROM THE MONMOUTHSHIRE MONCHIGU»T£-DYKE. 



