194 BRYOPSIS. 



ance till it had considerably extended itself, remarks, " that it does not 

 show the least tendency to throw up a frond. It has an uneven surface, 

 from taking the fonn of the rock, or even roots of coarse weeds, over which 

 it crosses.'' She considers it a true species. 



3. C. amphibium, Moore ; fronds minute, erect, cylindri- 

 cal, simple, obtuse, aggregated in widely-spreading strata. 

 Moore and Harv. An. Nat. Hist. xiii. p. 321 ; Harv. Phyc. 

 Brit. t. xxxv. B. 



Turf banks, near high-water mark, but washed by every tide, at Round- 

 stone, and at the head of Birtirbui Bay, Galway, Mr. Wm. M'Calla. 

 Tufts widely spreading, the bases composed of entangled fibres, among 

 which rise numerous mamillaeform fronds, from a quarter of an inch to an 

 inch in height, usually simple, rarely emarginate or forked ; having exactly 

 the structure of the frond of C. tomentosum. It differs from the young of 

 that species not merely in habitat, but also in having the fronds densely 

 tufted together, not solitary or dispersed. The colour is a herbaceous 

 green, and the substance soft. 



4. C. tomentosum, Huds. ; frond cylindrical, dichotomous. 

 Grev. Alg. Brit. p. 185, t. 19; Hook. Br. Fl. ii. p. 318; 

 Wyatt, Alg. Damn. No. 35; Harv. Phyc. Brit. t. xciii. 

 Fucus tomentosus, E. Bot. t. 712. 



On rocks in the sea ; frequent. Perennial. Summer. Frond rising 

 from a spreading spongy base, cylindrical, from a quarter to nearly half an 

 inch in diameter, 6 12 inches long, more or less regularly divided in a 

 dichotomous manner ; sometimes regularly dichotomous ; sometimes pal- 

 mato-partite, the segments forked; sometimes beset with short lateral 

 branches. Structure filamentous, the centre composed of longitudinal, in- 

 terlaced, colourless fibres, the circumference of radiating, horizontal, club- 

 shaped, deep green filaments, invested by a viscid gelatine. Fructification : 

 dark green ovate vesicles, borne by the club-shaped filaments. 



II. BRYOPSIS. Lamour. [Plate 24, B.] 



Frond membranaceous, filiform, tubular, cylindrical, glis- 

 tening, branched; the branches imbricated, or distichous 

 and pinnated, filled with a fine green, minutely granuliferous 

 fluid. Grev. Name, @puov, a moss, and u^is, an appearance. 



1. B. plumosa, Huds.; frond filiform, branched, naked 

 below, the branches scattered, spreading, twice or thrice 

 pinnated, the pinnae pectinated. Grev. Alg. Brit. p. 187, 

 t. 19 ; Hook. Br. Fl. ii. p. 318 ; Wyatt, Alg. Damn. No. 128 ; 

 Harv. Phyc. Brit. t. iii. Ulva plumosa, E. Bot. t. 2375. 



On rocks, &c., in tide-pools. Annual. Summer and autumn. Frond 

 1 4 inches high, more or less branched, sometimes with a nearly simple 

 stem, set with numerous close branches ; at other times much divided in 

 a subdicholomous or irregular manner. Branches naked at base, in the 

 upper part closely pinnated with subopposite, slender, distichous or rarely 



