ULVACE.E. 255 



Enteromorpha Hopkirkii. Hopkirk's Entero- 

 morpha. 



Frond from a few inches to a foot long, much branched, 

 very slender, soft in texture ; branches erect, alternate 

 or opposite, repeatedly divided, tapered ; branchlets awl- 

 shaped, minute, composed of a single series of cells, and 

 consequently jointed. Fructification, granules of endo- 

 chrome in the centre of large transparent cells. 



The recorded habitats of this species are not numer- 

 ous. It was first found at Torbay by Mr. Griffiths, and 

 subsequently at Carrickfergus by Mr. M'Calla. It also 

 occurs on the coast of North America ; but does not 

 appear to attain so large a size there as in this country. 

 Its distinctive character is the large size of the cells of 

 which its fronds are composed. 



Enteromorpha percursa. The spreading Entero- 

 morpha. 



Fronds hair-like, simple or rarely branched, growing in 

 tangled masses, composed of small square cells, which are 

 nearly filled with endochrome. 



This is an insignificant species, whose identity is not 

 by any means satisfactorily determined. 



Enteromorpha Ralfsii. Ralfs's Enteromorpha. 



Fronds hair-like, simple or rarely branched, long and 

 slender, composed of large transparent cells, each of which 

 contains a granule of bright green endochrome. 



This is another doubtful species, and the information 

 concerning it is meagre and confused. 



