52 THE MARINE BOTANIST. 



concentric lines, the cells of the surface radiating". 

 Fructification roundish or irregular, scattered sori 

 bursting' through both surfaces of the frond. 



ZONARIA PARVULA.— SMALL ZONARIA. 



Fronds procumbent, of an olivaceous green colour, 

 one to several inches in diameter, spreading over the 

 rocks in patches, and attached by whitish fibres, 

 except at the margins, which are full and lobed ; 

 the lobes are rounded, smooth, entire, and often 

 imbricated. Substance membranaceous, somewhat 

 transparent, and highly reticulated 5 the cells are 

 four-sided. On British plants the fructification 

 has not been observed, but it is described on 

 Swedish specimens by Dr. Areschoug. Grows 

 attached to rocks and corallines between tide- 

 marks, and in four to fifteen fathom water. An- 

 nual. Spring and Summer. Found all round the 

 coast. 



