RHODOSPERME.E. 



SYNOPSIS OF THE ORDERS OF RHODOSPERMEtE. 



Series 1. DESMIOSPERME^E, J. Ag. Sporiferous nucleus (either naked, immersed 

 in the substance of the frond, or lodged in lioUow conceptacles) consisting of 

 tufted spore-threads attached to a basal, parietal, or central placenta. Single 

 spores formed in each cell of the spore thread, or only in the terminal cell. 



1. Nucleus lodged in an external^ ovate or spherical conceptacle. 



* Placenta in the base of the holloio conceptacle. Spores pyri/orm or obconic, formed 

 in the terminal cell of the spore threads. 



1. Rhodomelace^. Frond articulate or furnished with an articulated polysiphonous 



axis ; the surface areolated. Spore-threads simple. Tetraspores seriated in the 

 ramuli, or in podlike receptacles. 



II. Laurenciace^. Frond inarticulate, solid, or tubular and septate ; the surface 



cells minute. Spore-threads simple or paniculate. Tetraspores irregularly 

 scattered through the ramuli. 



** Placenta in the base of the hollow conceptacle. Spores roundish or elliptical, in 

 moniliform strhigs ; all the cells of the spore-thread gradually changed into spores. 



III. CoRALLiNACE^. Froni calcareous (its ccUs Secreting Carbonate of lime). Spoi'e- 

 threads separating at maturity into four spores. 



IV. SpiLffiROCOccoiDEiE. Frond cartilaginous or membranaceous. Spore-threads 

 separating at maturity into many spores. 



*** Placenta axial, or suspended by filaments in the cavity of the external or half 

 immersed conceptacles. 



V. GelidiacetE. Fro?id inarticulate, cartilaginous or horny, opaque ; the axis (at 



least) formed of elongated, confcrvoid filaments. 



2 . Nucleus not lodged in a hollow conceptacle. 



* Nuclei contained in wart-like excrescences. 



VI. SpONGiocARPEiE. Frond cartilaginous (cylindrical) almost wholly composed of 

 confcrvoid filaments closely set in firm gelatine. Nuclei numerous in each 

 wart, globose. Spores obconical, radiating from a central point. 



