( r.i: LM1 mi E. 1 13 



Ceramium Plumula, Ag. Conferva Plumula, Ellis. C Turneri, 



Uh. 

 huh. ( )n rocks :m<l A 1 ir-t", near low-water mark, and in four to 

 fifteen fathoms water. Annual. Summer. 

 A very charming plant, though ;i common one; com- 

 mon, not merely <>n the shores of Europe, but dispersed 

 far and wide through tip- ocean, north and south of the 

 Line. The characters of the species are Btrongly marked, 

 and once seen, cannol be forgotten. Would thai others of 

 this beautiful genus were equally constant ! Here every 

 articulation, withoul exception, through the whole plant, 

 its pair of comb-like branchlets. Under the micro- 

 scope, therefore, Cal. Plumula cannol well be mistaken. 

 But, notwithstanding iliis perfed regularity of branching, 

 specimens differ much in Luxuriance, and consequently in 

 outer aspect; and wo mighi enumerate two varieties, in 

 one of which the combs are twice as long as in the other, 

 and more delicate. 



250. cruciatum (The crossed Callithamnion) ; filaments densely 

 tufted, irregularly and rather sparingly branched; branches 

 alternately divided, jointed, furnished at each joint with two 

 to four opposite or quaternate, slender, Bhort, pectinato-pin- 

 nate ramuli; tetraspores elliptical, subsessi in the 



lowermost joints of the ramuli, Ag. Syst. Al<j. r. 'J.. t >. l(>o. 

 (Atlas, PI. LV. Fig. 255 

 Callithamnion pumilum, Harv. 



JI'ilj. On mud-covered rocks, near low-water mark. Annual. 

 Summer. Bather rare. 

 A very distinct and beautiful species of this charming 

 genus, and one which i^ very widely distributed. It is not 

 i r Bubjecl to much variation, except of a very minor 

 iter. The < >r quaternate pinnulated ramuli 



constantly mark it. I .dividual* the joints ^{^ the 



stem are much Bhorter, the ramuli more dense, and the 

 whole planl very small. These, before I \\;i^ well ac- 

 quainted with tl 



distinct species, which I described 

 under the nam-' of pumilum, in the ' British Mora.' A bet- 

 ter acquaintance with the species has shown that this view 

 cannot he maintained. An excellent mark \\>v < 

 //////. by which it may he Known at a glance, lies in the 



i hi;- terminating the bn 

 unde\ eluded rai. 



