V. RHODYMENIACE.E. 155 



the same, showing part of the peripheric stratum, of the fibro-cellular wall and 

 placenta, and of the tufts of spore-threads issuing from the latter ; more or less 

 magnijied. 



VI. CORDYLECLADIA. J. Ag. 



Frond filiform, irregularly branched, carnoso-cartilaginous, formed of two strata 

 of cells ; medullary layer of oblong, longitudinal cells, cortical of roundish, 

 coloured, sub-seriated, vertical minute cellules. Conceptacles sessile on the branches, 

 sub-spherical, furnislied with a cellular pericarp at length perforate, containing a 

 densely packed globular mass of roundish-angular spores, formed by the evolution 

 of much-branched filaments issuing from a basal placenta. Tetraspores immersed 

 in the periphery of pod-like ramuli, oblong, cruciately parted. 



The type of this genus is Gracilaria erecta, Grev. (Harv. Phyc. Brit. t. 177- ) ; 

 a little plant, known only on the shores of the British Islands. In the above quoted 

 figure, which in other respects is characteristic, the tetraspores are incorrectly re- 

 presented as being zonate.^ instead of cruciate, as I find them to be on a renewed exa- 

 mination. The two following species are only doubtfully referred to this genus, 

 their fruit being as yet unknown. 



1. CoRDYLECLADiA ? Huntii ; fronds densely tufted, springing from a common, 

 expanded, crust-like disc, livid purple, tereti-compressed, once or twice forked or 

 secundly branched ; branches subulate, attenuate, acute ; fruit . . . . ? 



Hab. Narragansett Bay, Mr. Geo. Hunt. (v. s. in Herb. T.C.D.) 



Common crustaceous base, an inch or more in diameter. Fronds densely tufted, 

 2 — 3 inches high, setaceous below, twice as thick as hog's bristle above, evidently 

 compressed, especially in the upper portion, erect, sub-simple, irregularly divided ; 

 sometimes once or twice forked, sometimes with one or two secund lateral branches, 

 sometimes both forked and secundly branched. Branches filiform, attenuated, 

 acute. Fruit unknown. Colour a livid purplish, fading into white. Substance 

 cartilaginous, rather soft, adhering to paper in drying. Medullary stratum com- 

 posed of polygonal cells, filled with granules and smaller towards the margin ; 

 cortical of minute, coloured sub-seriated cells. 



In the absence of fruit this must remain doubtful. 1 liave as yet seen but a 

 single specimen, which 1 place in this genus from its strong outward resemblance 



X 2 



