178 BRITISH SEA-WEEDS. 



Gymnogongrus Grifnthsise. Mrs. Griffiths's 

 Gymnogongrus. 



Root an expanded disc; fronds densely tufted, one to 

 three inches high, simple at base, then repeatedly forked ; 

 branches flexuous and tapering, except at the tips, which 

 are sometimes slightly flattened. Tetraspores cruciate, 

 elliptical, formed of the upper joints of necklace-like fila- 

 ments, massed together in warts, either on the side of the 

 frond, or encircling it. 



This plant is perennial, and grows between the tide- 

 marks. It is in perfection in autumn and winter, when 

 it is generally thickly studded with nemathecia. These 

 should be examined under a microscope, for they are 

 extremely beautiful. The tetraspores are of a delicate 

 pink colour, transparent and sparkling, and are arranged 

 in chains, which a slight effort of the imagination will 

 easily convert into necklaces of tiny rubies. 



Gymnogongrus Norvegicus. The Norwegian 

 Gymnogongrus. 



Stem short, cylindrical; fronds linear, flat, repeatedly 

 forked, two to three inches or more high, more or less 

 tufted; the axils of the branches spreading, rounded, the 

 tips blunt. Spores very numerous, in minute, depressed, 

 spherical conceptacles, immersed in the upper segments of 

 the frond, and projecting on both sides ; tetraspores in 

 stalkless nemathecia, which are thickly scattered over both 

 sides of the frond. 



This species was formerly known as Chondrus Nor- 

 vegicus, but has been removed to its present position 

 by Professor Agardh. It is not very common, nor are 

 its characters easily recognized. Although called Norve- 



