CRYPTONEMIACE^. 159 



SYNOPSIS OF THE NORTH AMERICAN GENERA. 



Sub-order 1. GIGARTINE^E. Nucleus corn-pound ; consisting of several congre- 

 gated nucleoli, or roundish masses of spores. 



Tribe 1. Ttlocarpe^ : Frond rigid, compact ; its inner stratum composed of 

 roundish, polygonal cells ; its outer of closely packed, vertical, minute fila- 

 ments. Tetraspores contained in external, raised sori or warts. 



* Frond leaf -like, fiat. Conceptacles external. 



I. Stenogramiia. Frond dichotomous, membranaceous, rose-red. Conceptacles 



linear, rib-like, medial on the lobes of the frond. 



II. Phtllophora. i^?'on(istipitate,flabelliform, cleft. Cbnceptocfe roundish, scattered. 



** Frond linear, compressed or filiform. Conceptacles immersed. 



III. Gtmnogongrus. Frond sub-terete, compressed or flattish, sub-cartilaginous. 



IV. Ahneeltia. Frond terete, horny. 



Tribe 2. Kallyivienie^ : Frond membranaceous or coriaceous, its inner stratum 

 composed either of longitudinal filaments, or of polygonal cells surrounded by 

 a net-work of filaments ; its outer stratum of roundish or polygonal cells, 

 smaller towards the circumference, the cortical cellules disposed in minute 

 vertical filaments. 



* Frond cylindrical, alternately decompound. 



V. Cystoclonium. 



** Frond flat, its inner stratum composed of large, roundish cells, surrounded by a nei- 



tcork of anastomosing filaments. 



VI. Callophyllis. Frond dichotomous. bright red. 



D 



*** Frond flat, its inner stratum composed of longitudinal, interlaced filaments. 

 VII. Kallykenia. Frond sub-sessile, expanded, indefinite in form. 



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