Plate XXXIX. 



Fig. 177. NITOPHYLLUM LACERATUM. 



Colour. Dull-purplish, or brownish-red. 



Substance. Membranaceous. Extremely thin; cracking when dry. 



Character of Frond. A flat, ribless expansion; unstalked (sessile); much slit and 

 divided in a forked manner {dicJiotomously). The divisions (lacinice) sometimes 

 narrow, like those of the narrow variety of N. punctatum (see Plate XXXVIII. 

 Fig. 174, the upper form); sometimes as broad as those of N. Gmelini (Plate 

 XXXVIII. Fig. 176); generally obtuse; margins either smooth and even or 

 curled; or fringed with small leafy frondlets. Distinctly marked veins rising 

 from the base and spreading upwards. 



Measurement. From 2 to 10 inches long. 



Fructification. Of two kinds. 1. Clustered spores in globose capsules; scattered. 

 2. Tetraspores in oblong groups (sori) disposed along the margin, or in the 

 fringing leaflets. 



Habitat. Our coasts generally. Near low-water mark. Common. 



The only Nitopliyllum which reflects prismatic colours in the water. A variety 

 has all the tips of the divisions turned in like hooks, and clings by them to 

 the small algie near. For other Nitoployllums see Plate XL. Figs. 181 and 185. 



Fig. 178. PLOCLAMIUM COCCINEUM. 



Colour. Bright pink-red; particularly after a short exposure. 



Suhstance. Elastic, though thin; not easily tearing. Griving out a pleasant scent in 

 fresh water. 



Character of Frond. Flat, or nearly so; very narrow; tufted; excessively branched. 

 Main stems irregularly divided; thickly set with alternate, spreading branches, 

 which are furnished throughout with short-curved, pointed branchlets. 

 Branchlets simple, or furnished on their inner face with a smaller set of short- 

 curved, pointed branchlets, arranged four in succession; these sometimes re- 

 branchleted in a similar manner; the compound branchlets resembling little 

 combs. All the frond at one level as if cut out of paper. 



IleasuremeJit. From 2 to 12 inches long.. 



Fructification. Of tw^o kinds; external. 1. A mass of minute spores in globose 

 capsules, unstalked; borne on the edge of the upper branches. 2. Tetraspores 

 in minute, simple, or branched Stichidia; on the branchlets. 



Ilahitat. Our coasts generally. On rocks and the larger algne, at low- water mark, 

 or beyond. Common and abundant. 

 3 



