A New British Freshwater Alga. 43 
Fio. 1. Cross section of Cladophoya showing E. Cladophoya, well matured, 
penetrating cell-wall of host, and branches anastomosing to form compact 
thaiius round host. 
Fig. 2. Cross section of Cladophoya showing how E. Cladophoya penetrates 
between laminae of cell-wall of host. 
Fig. 3. This represents a further stage of process shown in Fig. 2. 
Fig. 4. Longitudinal section of Cladophoya showing terminal segment of 
branch. Surmounted by thallus of E. Cladophoya. All figures x 540. 
^>=pyrenoid. c=chloroplast. K=nucleus. s=starch-grain. 
