gelidiacejE. 149 



divided ; the upper branches once or twice forked, ending 

 in fan-shaped, many-cleft branchlets; the branches and 

 branchlets fringed with short, slender, pointed cilia. Spores 

 in spherical conceptacles, embedded in the cilia ; tetraspores 

 not known. 



The bright red colour and coral-like form of this 

 handsome species are very obvious characters, and 

 there is no other British Sea-weed for which it can be 

 mistaken. It grows on rocky shores, at or beyond 

 low-water mark, during summer and autumn, and is 

 perennial. Unless a dredge be used, only washed-up 

 or floating specimens can be obtained, but these are 

 always suificiently numerous. This plant is moderately 

 abundant on our south and west coasts, but rare in 

 Scotland. It does not adhere very closely to paper, and 

 shrinks much in drying. 



Order XII. GELIDIACEiE. 



Purple or Med Sea-weeds with a cartilaginous or horny, 

 opake frond, without joints, composed of elongated, hair- 

 like f laments. Spores attached to slender threads or to 

 a fibrous placenta, in conceptacles, which are irregularly 

 immersed in the frond. 



Genus LVI. GELIDIUM. 



Prond gristly, linear, flattened, irregularly branched, com- 

 posed of three strata of cells : those in the centre very long, 

 and densely interwoven ; the next series small, many-sided, 

 set in diverging lines ; those on the surface minute, ar- 

 ranged in necklace-like threads at right-angles with the axis. 

 Spores pear-shaped, in two-celled conceptacles immersed 

 in the branchlets ; tetraspores cruciate, embedded, in irre- 



