PLATE XVIII. 



io. 



1. MEMBRANIPORA MONOSTACHYS, p. 131; nat. size, show- 

 ing the linear habit of growth. 



2. , a colony, including one of the rudi- 

 mentary cells. 



3. - , var. FOSSARIA. 



4. , var. FOSSARIA : two zocecia, viewed 

 sideways. 



5. MEMBRANIPORA MEMBRANACEA, p. 140. 



6. , with a number of abnormal cells ("towcr- 



zocecia" of Nitsche). 



7. MEMBRANIPORA HEXAGONA, p. 143. After Busk. 



8. SCHIZOPORELLA HYALINA, p. 271 ] a colony with 



suborbicular orifice. 



9. , with the ooecia borne on imperfectly 



developed cells. 



10. - , var. with hyaline walls and the lower 



margin of the orifice deeply sinuated. Sec Plate 

 XLV. figs. 2 and 3. 



