190 BRITISH SEA-WEEDS. 



broad, very variably divided, sometimes quite simple, at 

 others many times forked and proliferous, always gelatinous. 

 Spores in minute dots, abundantly scattered over the whole 

 frond. 



Although subject to extreme variation of size and 

 form, this is not a difficult species to determine. The 

 gelatinous texture of the frond, taken in conjunction with 

 its general character, always affords a ready means of 

 identification. I have collected many specimens in 

 Jersey, where the plant is moderately abundant in sum- 

 mer. It is annual, and grows on rocks near low- water 

 mark, and at greater depths, whence it is cast on shore. 

 Specimens dry easily, and do not require to be much 

 pressed. 



Genus LXXXVII. FURCELLARIA. 



Frond, cylindrical, forked, solid, composed of three kinds 

 of cells ; those in the centre longitudinal, elongate, inter- 

 woven ; those of the next series roundish, large ; and those 

 of the outer, or bark series, small, arranged vertically in neck- 

 lace-like threads. Spores large, angular, arranged in nuclei 

 (favellse), which are immersed several together, in the pod- 

 like tips of the branches ; tetraspores large, pear-shaped, 

 zonate, formed just within the external layer of cells, from 

 the outer fibres of the intermediate layer. — Furcellaria, 

 from the Latin furcula, a little fork. 



It is a remarkable result of the new system of clas- 

 sification, based on the mode of fructification, that 

 two genera so much alike in their general characters 

 as Polyides and Furcellaria should be so widely sepa- 

 rated. 



