118 NITOPHYLLUM. 



about equal in length. Substance very thin and delicate, closely adhering 

 to paper. Tubercles scattered over the frond ; spots of tetraspores smaller 

 than in N. punctatum, larger than in N. Hilliee, scattered over the surface 

 and segments. 



4. N. Gmelini, Laraour. ; frond with a short stalk, more 

 or less fan-shaped, with a roundish outline, variously cleft 

 into broadly wedge-shaped segments, waved, curled, and 

 rather crisp, marked near the base (and sometimes over the 

 surface) with vague vanishing nerves ; spots of tetraspores 

 linear, confined to the margin. Grev. Alg. Brit. p. 82 ; 

 Hook. Br. Fl. ii. p. 288 ; E. Bot. Suppl t. 2779 ; Wyatt, 

 Alg. Damn. No. 65 ; Harv. Phyc. Brit. t. ccxxxv. 



On rocks and Laminaria:, &c. ; rare. Annual. Summer. Shores of 

 England and Ireland. Stem short, cartilaginous, expanding into a broadly 

 fan-shaped or roundish frond, 2 4 inches, or in the Irish specimens 6 

 inches in breadth, more or less deeply cleft ; its surface traversed by vague 

 veins, which are very evident in some specimens, in others faint ; the mar- 

 gin smooth and even. Tubercles scattered over the surface ; spots of tetra- 

 spores confined to the margin, long and linear. Substance membranaceous, 

 crisp, and somewhat rigid when first gathered. Colour a purplish red. 

 Some specimens are scarcely cleft, others are divided nearly to the base 

 into ribbon-like segments, but all preserve a roundish outline. 



5. N. laceratum, Gmel. ; frond sessile, much divided in a 

 dichotomous manner, marked with flexuous veins ; segments 

 mostly linear, variously cleft, waved or fimbriate at the mar- 

 gin ; spots of granules oblong, either marginal or borne 

 on distinct leafy processes of the margin. Grev. Alg. Brit, 

 p. 83; Hook. Br. Fl. ii. p. 288; Wyatt, Alg. Danm. No. 

 107; Harv. Phyc. Brit. t. cclxvii. F. laceratus, E. Bot. t. 

 1067. 8. uncinatum ; fronds narrow, the lesser segments 

 hooked. 



Attached to Algae, corallines, &c. ; common. Annual. Summer. 

 Fronds 210 inches in length, much and dichotomously divided, marked 

 in the lower part with vague, flexuous, branching veins ; the segments of 

 various lengths, linear wedge-shaped ; the margin either smooth and even, 

 or waved, crenate, or fringed with processes. Tubercles scattered ; tetra- 

 spores either in marginal spots, or in leafy processes. /3. is a much 

 smaller state, having the ends of the branches hooked into the form of a 

 sickle. 



6. N. versicolor, Harv. ; stem cartilaginous, elongated, 

 simple or branched, suddenly expanding into a broadly fan- 

 shaped, variously cleft frond, of a thickish-membranaceous, 

 highly reticulate substance and rose-red colour, becoming 

 golden-orange in fresh -water; the segments rounded ; the 

 apices generally thickened into hard, expanded calli ; fructi- 

 fication unknown. Harv. Phyc. Brit. t. ix. 



