the Briti/I: Fuci, tJuhh parl'tcular "Defcriptions of each Species. 143 



21. FUCUS SERRATUS. 



F. fronde dichotoma ferrato-dentata, apicibus plants tubercu- 

 latis obtufis. Herb. Linn. Buddie, p. 8. optima. Petiver, 

 p. 28. «. I. Uvedale^ vol. I. p. 1. «. 2. and p. 3. Mori/on, Hi/I. 

 Oxon, iii. / 15. /. 9. /. I. /?. 4y»- P- 42. «• 7. ^^7, Pnrif. 

 1711. //. 9, 10, et lyiz parlU ide, pi. 3./. 1, 2, 3, 4, 5, 7. 9. 

 Lwff. 5/. P/. 1626. Syjl. Fl. Avg. p. 576. Fl. Scot. 902. 

 IVithering, vol. 3. /. 241. Stackhoufe, Ner. But. p. i. /. i. 

 Habitat in rupibus et faxis I'ubmarinis paflim. 

 Radix callus expanfus, attamen nervi quidam fuperne extant, 

 quafi ex fibris coadunatis conftaret — Frons pedalis bipedalis, plana, 

 alata, dichotoma, obtufa, marginibus profunde arguteque ferratis — 

 Per totam paginam puniSla prominula fparfa — Apices obtnfi, erofo- 

 iientati plani, tuberculati, tuberculis plurimis confertis, prominulis 

 — Color olivaceus — Subjlantia cartilaginea. 



/ro«i variat ramofa et ramofifTima j argute et crenato-ferrata; lata 

 et angufta, at femper {errata, apicibus obtufis planis tuberculatis. 



There can be no difficulty in determining this fpecies, in what- 

 ever ftage of its growth it may be found. The fingularity of its 

 root, having nerves or fibres Handing out above the lurface of the 

 callus, thus conneiSting the folid and fibrous rooted Fuci, the edges 

 being conftantly ferrated, and the ends of the branches plain and 

 not fwelled, arc marks by which a child may diftinguilh it. This 

 fpecies never has bladders. 



The plate in J5l. Pari/. 1712, which we have referred to, (hews 

 the plant in all the ftages of kj growth. 



Little points are obfervable en the membranous parts of all 

 the branches. Nothing chara<3eriftic (as we have cbfervcd in our 

 preface) can be drawn from them ; for they arc alike obfervable 



upoa 



