Fig. 15. FUCUS CANALICULATUS. 



Colour. When fresli^ olive-brown^ or clear olive-yellow. 

 Substance. Tougli^ leathery; but not coarse. 



Character of Frond. A tuft of narrow fronds from a root; branched. Branch- 

 ing repeatedly forked {dicJiotomous) . Every part of the frond chan- 

 nelled or grooved on one side. 



Measurement. From 2 to 6 inches long; from to J of an inch wide. 



Air-vessels. JSTone. 



Fructification. Minute seeds [spores) in special receptacles at the ends of the 

 branches. Receptacles oblong; two from each tip forming a fork; 

 lighter-coloured than the frond; slimy. 



Hahitat. Our rocky shores generally. Between high-water mark and half- 

 tide level. 



TSTow Fucodium canaliculatum. A pretty plant, and clearly marked by the 

 groove or channel in its very narrow fronds, and by its growth in bushy tufts. 



Fig. 16. HIMANTHALIA LORE A. 



Colour. When fresh^ olive; when dry^ black. 

 Substance. Tough^ leathery. 



Character of Frond. Like a tiny leather peg-top standing upright. By de- 

 grees the top sinks in^ and becomes cup-shaped. In the second year 

 of growth^ but not till then_, it throws out long_, strap-shaped recep- 

 tacles from its centre. 



Measurement. Frond, a-bout an inch high; receptades from 2 to even 20 feet 

 long; from \ to \ of an inch wide. 



Air-vessels. None. 



Fructijication. Minute seeds [spores) in special receptacles springing from the 

 centre of the frond^like narrow thongs of leather; several times branched 

 in a forked manner [dichotomously) ; dark olive-green; slimy. 



Hahitat. On rocky shores generally. From low water-mark up to half-tide level. 



Eocks covered with the long slimy receptacles of this plant are dangerous 

 walking ground. The usual comparison of a peg-top is retained in the above 

 description; but to some eyes the one-year-old fronds of this species look like 

 pale olive-coloured mushrooms or buttons, dotted about the rocks. The recep- 

 tacles have a special jDarasite of their own; Elachista scutulata ; a minute alga 

 dotted about the thongs, like dark warts; for which see Plate XVI. Fig. 65. 

 And another of the same family is frequently met with upon them ; Elachista 

 velutina; see Plate XYI. Fig. 67. 



8 



