V. CRYPTONEMIACE^. I99 



surface, simple, containing, within a gelatinous hyaline pellicle, numerous roundish- 

 angular spores, which are at length discharged through a superficial pore. Tetra- 

 spores immersed in the cortical layer, scattered, cruciate. 



Fronds dark brownish red or purple, sometimes livid, changing to green in decayi 

 strongly compressed or flat, narrow- linear or rarely cuneato-lanceolate, very gene- 

 rally pinnately decompound, rarely dichotomous ; of a compact structure, and soft, 

 membranaceo-gelatinous or carnoso-coriaceous substance, very tough when recent, 

 lubricous, and difficult to detach from the rock on which they grow, membra- 

 naceous when dry, shrinking much, and generally closely adhering to paper. The 

 spor'iferous nuclei are sunk in the frond, but slightly prominent, like little pimples, 

 to either surface, often of small size, and often aggregated in considerable numbers. 

 They communicate with the surface by means of a canal which runs from the 

 nucleus through the cortical layer of the frond, its mouth appearing as a superficial 

 pore. The species are natives of the Tropical Ocean and of the warmer regions of 

 the Temperate zone. One {G.jUicina) is found as far north as the south of Eng- 

 land. 



1. Grateloupia Gibbesii ; frond (one to two feet long) flat, cuneate at the base, 

 polymorphous ; lanceolate or wedge-shaped, simple, forked, or alternately multifid ; 

 the laciniae very long, lanceolate, acute ; margin entire or repand, or fringed with 

 linear lobes which sometimes lengthen into pinnae ; conceptacles immersed in the 

 lamina, minute, scattered. (Tab. XXVI.) 



Hab. On the breakwater at Sullivan's Island, Charleston, South Carolina, Prof. 

 Lewis R. Gihhes and W. H. H.^ January, 1850. (v. v.) 



Fronds densely tufted, six, twelve, twenty inches in length, the lacinias from half 

 an inch to an inch and half wide at the widest part, tapering very much to the base 

 and apex, flat, coriaceo-meml^ranaceous, and rather thin, with the feel of fine kid 

 leather. The ramification is so difi'erent in different specimens, that an adequate 

 conception of the species can hardly be obtained without the comparison of many 

 individuals. In some the frond is quite simple, lanceolate or cuneate, the margin 

 flat, naked, or winged with lanceolate lobes on one or both sides. In others the 

 frond divides at an inch or two above the base into ten or twelve lacinise ; each 

 several inches long, tapering greatly to both extremities, either perfectly flat and 

 entire or with the margin undulate and repand, now and then furnished with a few 

 secund pinnaj. Other specimens have the lacinia? forked or even palmate near the 

 apex ; and in others a primary, linear lamina is pinnated throughout with linear- 

 cuneate, simple or forked lobes. In fact, in the same tuft scarcely two specimens 

 are similarly branched. Colour^ when growing, a very dark, blackish purple ; 

 changing more or less completely to a livid green in drj'ing. Conceptacles, which 



