Plate IV. 



Fig. 13. FUCUS NODOSUS. 



Colour. WliGn fresli^ olive-green; glossy; yellower in youtli; wlien dry, black. 

 Snhstance. Densely tougli and leathery. 



Cliarader of Frond. Compressed narrow straps, several springing from a 

 root; thick; branched. Branching partly forked [dicliotomous) , partly 

 on each side of a stem, like a feather [jpinnate). Margins toothed 

 [serrated] at remote intervals. 



Measurement. From 2 to 6 feet long. 



Air-vessels. Inflations in the branches, swelling them out far beyond the mar- 

 gins; very large, oblong. 



Fructification. Minute seeds [sjporcs] in special receptacles at the sides of the 

 branches. Receptacles, globose; on stalks; growing from the axils of 

 the marginal teeth; slimy; bright yellow. 



Hahitat. All round the coast; very common; between high-water mark and 

 half- tide level. 



ISTow Fucodium nodosum. 



Fig. 14. FUCUS MACKAII. 



Colour. When fresh, dull olive-green; when dry, black. 

 Substance. Tough, leathery; when dry, rather horny. 



Clha,racter of Frond. Cylindrical except at the base; slender; branched. 

 Branching forked [dicliotomous] . Branches crowded, spreading. 



Measurement. From 6 to 10 inches long. 



Air-vessels. Inflations in the branches; here and there one, alone; longisli 

 oval; wider than the branch. 



Fructification. Minute seeds [simres) in special receptacles at the sides of the 

 branches towards the base. Receptacles on long drooping stalks; more 

 or less ovate; sometimes one, sometimes two from a stalk; the two 

 forming a fork. 



Hahitat. West of Ireland. On muddy sea-shores. Not rooted, but resting 

 on mad or in gravel among large stones. 



Now Fucodium Maclcaii. 



