( 150 ) 



four large central cells, surrounded by longitudinal series of smaller ones. 

 Substance very rigid, not adhering to paper. Colour, a greenish-olive. 



One of our rarest and prettiest species, and one which seems to find 

 its northern limit on our southern shores, where it is even rare. It 

 is said to grow to a much greater size on the shores of southern 

 Europe, where it is much more common. We are not aware of any 

 Scotch locality or any in the north of England. 



It is said to have been found in fructification in Jersey by Miss 

 Turner, but we have seen no fruit. 



Like most perennial Algse, its summer and winter habits are widely 

 different ; in winter the beautiful fern-like fronds becoming denuded 

 of their pinnules, so that it looks quite like a different species. This 

 Agardh appears to describe as a different species, under the name of 

 >S', simpliciuscula ; while Dr. Greville considered the British as different 

 from that found in the south of Europe, and has given it under the name 

 of S. hypnoides, as noticed in Phyc. Brit. 



EXPLANATION OF PLATE CLXXL 



Fig. 1. — Sphacelaria filicina, natural size. 

 2.— Portion of stem of pinna and pinnule. 

 3. — Joints of same. 

 4. — TransTerse section of stem. All masrnified. 



