DICTYOTACE^E, 63 



Genus XXTII. PTJNCTARIA. 

 Eoot shield-shaped. Frond membranous, simple, flat, 

 ■without a mid-rib. Fructificatioa in minute dots scattered 

 over the surface of the frond. — Ponctakia, from the Latin 

 punctum, a dot. 



This genus contains several species which are dis- 

 tributed on the shores of the Atlantic and in the Medi- 

 terranean Sea. Three of tlieni are moderately common 

 on our coasts. 



Punctaria latifolia. Broad-leaved Punctaria. 



Prond six inches to a foot long, and one to two inches 

 broad, oblong, tapering abruptly at the base, irregularly 

 waved and notched at the edge, of a thin membranous sub- 

 stance. 



This species grows on rocks and Algse in tide- pools. 

 It is annual, and in perfection in summer. I recently 

 gathered fine specimens in April at the back of Elizabeth 

 Castle, Jersey, 



Punctaria plautaginea. Plantain Punctaria. 



Frond four inches to a foot long, and from a quarter of 

 an inch to two inches broad, lance-shaped, gradually taper- 

 ing at the base, of a leathery, membranous substance, and 

 dark olive-brown colour. 



Dr. Harvey, in his ' Nereis Boreali- Americana,' sug- 

 gests that this is probably the type species, and that 

 P. lalifolia and P. tenuissima are only varieties. Pos- 

 sibly future botanists may so decide, but at present I 

 prefer to retain the three species as figured and described 

 in the ' Phycologia.' 



Punctaria tenuissima. Slender Punctaria. 



Frond two to eight inches long, and from one-tenth to 



