Ser. RHoDOSPERME. Fam. Ceramiee. 
Prats CCVI. 
CERAMIUM GRACILLIMUM, Grif. et Harv. 
Gen. Cuar. Frond filiform, one tubed, articulated; the dissepiments 
coated with a stratum of coloured cellules, which sometimes extend 
over the surface of the articulation. ructification of two kinds, on 
distinct individuals ; 1, ¢e¢raspores either immersed in the ramuli or 
more or less external; 2, sessile, roundish receptacles (favella), 
having a pellucid limbus, containing minute, angular spores, and 
subtended by one or more, short, involucral ramuli. CrRAmMiuM 
(Roth.),—from xepapos, a pitcher; but the fruit is not pitcher shaped. 
Crramium gracillimum ; frond excessively slender, of nearly equal diameter 
throughout, very flaccid and gelatinous, dichotomous ; the branches set 
with minute, flabelliform, dichotomous ramuli ; articulations colourless, 
those of the branches five or six times as long as broad, those of the 
ramuli very short; dissepiments opake, purple; favellee borne on the 
lateral ramuli, with a spreading, many-rayed involucre. 
CrraMivm flaccidum, Harv. in Herb. 
Hormoceras gracilliimum, Kitz. im Linn. vol. xv. p. 133. Kiitz. Phyc. Gen. 
p- 378. 
Has. On muscle shells and on Corallina officinalis and other small Alge, 
exposed at extreme low-water. Annual. September. Kilkee, coast 
of Clare, W.H.H. (1844). Mewstone, Plymouth, Rev. W. 8. Hore 
and Dr. Cocks. Penzance, Mr. Ralfs. Probably common. 
Gror. Distr. Mediterranean Sea. Atlantic coast of France. 
Descr. Fronds densely tufted, two or three inches long, much more slender than 
a human hair, exceedingly flaccid and tender, irregularly dichotomous or 
somewhat alternately divided; the principal stem and branches of nearly 
_ equal diameter from their base to the extremity, the forkings distant. 
Branches furnished at intervals of one or two joints with minute, alternate, 
dichotomous, flabelliform ramuli, a line or two in length, obovate in outline 
and level topped. -4pices incurved, but not strongly hooked. Articulations 
colourless ; those of the lower part of the stem many times longer than broad, 
of the branches gradually shorter ; and in the lateral dichotomous ramuli much 
shorter than their breadth, the terminal ones appearing like mere strie. 
Dissepiments opake, purple, swollen. Faved/e either on lateral ramuli, or on 
truncated branches, binate, globose, surrounded by elongated, forked invo- 
lucral ramuli. Tetraspores, I have not seen. Substance exceedingly tender 
and ae closely adhering to paper in drying. Colour, a dark, reddish 
purpie. 
I first met with this plant in the autumn of 1844, at Kilkee, 
