Geol. Mag., 1919. 



Plata; III. 



14- 



15 a 



16 



•3I:j ; ,- ;: .: 



.% 



cz 



17 





IS 





19 



F..4.C. deZ. 



%o 





iJuZe t£ Danichson. 



PORES AND CHANNEL-SYSTEMS IN MEGACYSTIS. 



16, 17, 18, Diffuse plan. 19, 20, 21, Concentrated plan. 



All figures enlarged 20 diameters. 



