Ceramiea.'] ceeamium. 197 



Genus XLI. CEEAMIUM, Rol/i. 



Gen. Char. Pilaments articulated, mostly dichotoinous, reti- 

 culated with, veins ; dissepiments opake, Fructification double : 

 1, capsules, with a membranous pericarp, simple or lobed, gene- 

 rally subtended by one or two short ramuli, and containing 

 numerous angular seeds ; 2, oblong granules, partially imbedded 

 in the joints of the lesser ramuli. — Name from a Greek word 

 signifying a little pitcher, in allusion to the shape of the capsules 

 in some of the species. — Harvey. 



It is not long since our British list contained only two or 

 three species of Ceramia; now we have, in the Phyc. Brit., 

 fourteen enumerated. 



1. Ceramium rubrum, AgardJi, (Plate YIII. fig. 29, is a 

 portion of Ceramium ruhrum, natural size, and the figure to 

 the left is a branchlet with a favella magnified.) 



Hab. On rocks and Algse. Perennial. Summer. Autumn. 



This plant is very common everywhere. It is from six to 

 twelve inches long ; the capsules are globular, subtended by 

 short ramuli ; colour, from a fine red to a dirty white. So 

 variable is it, that the young botanist Ihinks he has half-a- 

 dozen species at least in his vascuhim, when they all turn 

 out to be this Protean Ceramium rubrum, 



2. Ceramium diaphanum, Agardh, (Plate YII. fig. 27, 



