PLATE II 



Fig. I. Verrucaria serpuloides M. Lamb, associated with an encrusting 

 calcareous alga {Lhhophylluin sp.?) in a rock pool, Goudier Islet, 

 Port Lockroy. The Verrucaria is seen as a dark band, the upper 

 edge of which marks the level of lowest ebb tide. (Under-water 

 photograph.) Phot. I.M.L., 26. x. 1944. 



Fig. 2. Part of an extensive patch of Verrucaria elaeoplaca Vain., on a 

 natural gutter in the granodiorite rocks of Goudier Islet, Port 

 Lockroy, periodically moistened by a flow of snowmelt water. 

 \ nat. size. Phot. I.M.L., 20. xii. 1944. 



