184 CRYPTONEMIACEiE. v. 



Hab. In the Northern Pacific, Mertens. 



" Crust minute, tnberculose, adhering to stones. From this crust spring the 

 fronds, which are half an inch high, rarely an inch, more or less crowded, terete, 

 attenuate at each end, simple or twice or thrice forked, with patent branches. 

 Colour purplish. Substance cartilaginous." 



XIV. CRYPTONEMIA. J. Ag. 



Frond flat, rigidly membranous, sub-caulescent, proliferous or branched, com. 

 posed of three strata of cells ; the medullary of elongated, branched, densely inter- 

 woven filaments ; the intermediate of roundish cells, towards the surface passing 

 into the minute cells of the cortical layer. Nuclei (favellce) immersed, prominent 

 to one surface, simple, consisting of numerous roundish spores, contained within a 

 hyaline membrane, at length discharged through a superficial pore. Tetraspores 

 collected into roundish, wart-like sori, lodged either in special leaflets or beneath 

 the apices of the leaves, oblong, cruciate. 



Plants with the rigid substance and the external habit of Phyllofhora, from which 

 they are well distinguished both by the different structure of the frond and the 

 simplicity of the nucleus. This latter character, combined with the different dispo- 

 sition of the tetraspores and the rigid substance, distinguishes them from Kallymenia 

 to which the internal structure of the frond allies them. Six species are described, 

 four of which are peculiar to the southern shores of Europe, and two to the warmer 

 regions of America. One of these last is described below. 



1. Cryttonemia crenulata, J. Ag. ; stipes short, soon expanding into a broadly 

 cuneate, bifid or repeatedly forked frond, eroso-denticulate (or rarely sub-entire) at 

 the margin, and proliferous with similarly forked, broadly proliferous frondlets. 

 J. Ag. Sp. Alg. 2, p. 225. Phyllophora crenulata, J. Ag. Kiltz. Sp. Alg. p. 791- 



Hab. Common at Key West, Florida, W. H. H. (v. v.) 



Fronds densely tufted, about six inches long, with a short cylindrical stipes as 

 thick as a crow's quill and half an inch long, which rapidly expands into the cu- 

 neate base of a membranous, simple or forked lamina. This lamina is one to two 

 inches wide below the first fork ; its segments half an inch wide, linear or wedge- 

 shaped, with acute axils, obtuse or truncate apices, and generally an eroso-denticu- 



