216 CERAMIACEiE. v. 



Ultimate ramuli forcipate at the apex. Sometimes the lateral branches are few, 

 simply forked, and distantly scattered along the branches, eitlier alternate, or 

 secund ; sometimes they are very numerous, springing from nearly every node. 

 Internodes hyaline, destitute of cortical cells, those of the lower branches three or 

 four times as long as broad, the upper ones successively shorter. FaveUoe involu- 

 crate, mostly sessile near the ends of the lateral ramuli. Tetraspores either in the 

 ramuli or the main branches, densely whorled round the node, prominent. Colour 

 of the tuft a dark purple. Substance soft, adhering to paper in drying. 



5. Ceramium subtile^ J. Kg. ; " frond capillary, dichotomous, sub-alternately 

 branched above, branches elongate, set with patent, forcipate ramuli ; lower inter- 

 nodes twice or thrice as long as broad, upper successively shorter ; nodes scarcely 

 swollen ; tetraspores secund on the outer edge of the segments, rather prominent." 

 J. Ag.Sp. Alg. 2, p. 120. 



Hab. Vera Cruz, Gulf of Mexico, Liebman. 



Said to be allied to C. gracilUmum ; but is of greater diameter, with more patent, 

 by no means fastigiate ramuli, shorter lower articulations, less swollen nodes, and 

 differently disposed tetraspores. I have not seen any specimens. 



6. Ceramium tenuissimum, Lyngb. ; frond capillary, of equal diameter throughout, 

 rigid, dichotomous, excessively divided, fastigiate ; the axils very patent ; inter- 

 nodes colourless, those of the middle of the stem from four to six times as long as 

 broad, the upper successively shorter ; nodes swollen ; tetraspores very prominent, 

 secund on the outer edge of short lateral ramuli, one or more at each node ; favellte 

 involucrate, near the tips of short ramuli. /. Ag. Sj). Alg. 2, p. 120. Ceramium 

 nodosum^ Harv. Phyc. Brit. t. 90. Gongroceras nodiferwn, Kiitz. Sp. Alg. p. 678, 

 aho G. tenuissimum., Kiitz. I. c. p. 680. 



Hab. Key West, Florida, W. H. H., Prof. Tuomey, Mrs. Adams. Key Biscayne, 

 Prof. Tiiomey. (v. v.) 



Tufts two to three inches long, globose, fastigiate. Filaments much finer than 

 human hair, many times dichotomous with very patent angles and spreading 

 branches and ramuli. Apices diverging, forcipate. The lower forks are distant, 

 the upper gradually nearer. The lateral ramuli are either simple or forked, hooked 

 in or forcipate at the ends. They bear the fructification of both kinds. Colour, a 

 pale or dark purjilish red, changing to ferruginous-red in fresh water. Internodes 

 of the ramuli very short, of the lower branches successively longer, and .5 — 6 times 

 as long as broad in the lower part of the plant. Nodes generally swollen. 



The American specimens here described are destitute of fruit, and are so far, 

 therefore, uncertain ; but in other respects are very similar to European specimens. 



