CORALLINACES. 105 



group of Algae they are further allied by their colour and the 

 nature of their spores. 



The Order consists of two, or, if Lithocystis be rightly 

 placed in it, of three sub-orders, as follows : 



SYNOPSIS OF THE BRITISH GENERA. 



Suborder 1. CORALLINES. Frond filiform, articulated. 



I. CORALLINA. (Frond pinnated). Ceramidia terminal, 



simple. [Plate 13, C.] 



II. JANIA. (Frond dichotomous). Ceramidia tipped with 



two horn-like ramuli. [Plate 13, D.J 



Suborder 2. NULLIPORES. Frond crustaceous or foliaceous, 

 opake, not articulated. 



III. MELOBESIA. Frond stony, forming either a crusta- 

 ceous expansion, or a foliaceous, or shrub-like body. 

 [Plate 14, A.] 



IV. HILDENBRANDTIA. Frond cartilaginous, not stony, 

 forming a crustaceous expansion. [Plate 14, C.] 



Suborder 3 ? LYTHOCYSTES. Frond plane, hyaline, com- 

 posed of cells radiating from a centre. Fructification 

 unknown. 



V. LYTHOCYSTIS. (A minute parasite}. [Plate 14, B.] 



Suborder 1. CORALLINES. Frond filiform, articulated. 



I. CORALLINA. Linn. [Plate 13, C.] 



Frond filiform, articulated, branched (mostly pinnate), 

 coated with a calcareous deposit. Fructification, turbinate 

 or obovate, mostly terminal ceramidia, pierced at the apex 

 by a minute pore, and containing a tuft of erect, pyriform, or 

 club-shaped, transversely parted tetraspores. Name, from 

 Coralium, coral, which these plants resemble in having a 

 stony substance. 



