128 BRITISH SEA-WEEDS. 



four-parted, in urn-shaped conceptacles, which are formed 

 from the axillary articulations of the uppermost branches, 

 are furnished with a terminal pore, and are generally two- 

 horned. — Jania, from Janira, one of the Nereids. 



With the exception of the position of the spore-con - 

 ceptacles, the characters of this genus are the same as 

 those of Corallina, but all our British species may be 

 readily known by their much smaller size and more 

 slender make. 



Jania rub ens. Red Jania. 



Fronds about an inch long, forked, growing in tufts on 

 various sea-weeds ; articulations of the branches and 

 branchlets., cylindrical, about four times as long as broad 

 in the middle of the frond, shorter below, longer above. 

 The whole plant of a pale red colour, which is changed to 

 white by exposure. Spores in urn-shaped, horned concep- 

 tacles, at the tips of the branchlets. 



This is a very common plant, which may always be 

 easily recognized. The stems of Cladostephus verticil- 

 latus are constantly infested with it, so much so, indeed, 

 that it is sometimes difficult to find a specimen of that 

 plant perfectly free from this parasite, which grows less 

 frequently on several other sea-weeds. It is perennial, 

 and fruits in summer. 



Jania corniculata. The horned Jania. 



Fronds from one to two inches long, forked, growing in 

 tufts on various sea-weeds ; articulations of the branches 

 obconical, flattened, their upper angles sharp and prominent, 

 those of the branchlets cylindrical, thread-like. Spores in 

 urn-shaped conceptacles, in the axils of the upper branch- 

 lets. 



