Ser. MELiNOSPERME.fi/ Fam. Chordariea. 



Plate XXXI. 



MES0GL0IA VERMICULARIS, Ag. 



Gen. Char. Frond filiform, much branched, gelatinous. Axis composed 

 of loosely packed, longitudinal, interlaced filaments, invested with 

 gelatine ; the periphery of radiating, dichotomous filaments, whose 

 apices produce clusters of club-shaped, moniliform fibres. Fructifica- 

 tion, obovate spores, seated among the apical fibres. — Mesogloia (Ag.), 

 from fieo-os, the middle; and y\ows, viscid; in allusion to the gela- 

 tinous axis. 



Mesogloia vermicularis ; frond unequally distended, clumsy ; branches 

 irregularly pinnate, thick, worm-like, lineari-fusiform ; ramuli copious, 

 long, flexuous, resembling the main branches. 



Mesogloia vermicularis, Ag. Syn. p. 126. Lyngb. Hyd. p. 190. t. 65. Ag. 

 Syst. p. 51. Harv. in Hook. Br. Fl. vol. ii. p. 387. Wyatt. Alg.Danm. 

 no. 1 00. Kiitz. Phijc. Gen. p. 332. t. 27. f. 1. Menegh. Alg. ltd. et Balm. 

 p. 279. Endl. 3rd Suppl. p. 23. 



Trichocladia vermicularis, Harv. in Mac.Fl. Hib. part 3. p. 186. 



Helminthocladia vermicularis, Harv. Gen. 8. A. PI. p. 397. Harv. Man. 

 p. 45. 



Rivulaeia vermiculata, E.Bot. t. 1818. 



Ch,etophora vermiculata, Hook. Fl. Scot, part 2. p. 75. 



Hab. On rocks and stones in the sea, about half-tide level. Annual. 

 Summer. Common. 



Geogr. Distr. Atlantic shores of Europe. Mediterranean sea. 



Descr. Root small, discoid. Fronds tufted, 1-2 feet high, gelatinous, flaccid, 

 but elastic, with a leading stem, which is either simple, or but slightly 

 divided, somewhat flexuous, unequally distended and constricted at intervals, 

 tapering to the base and apex, and beset throughout its length with very 

 numerous, close, lateral branches. Branches similar in form to the stem, 

 of various length, patent, or horizontal, more or less clearly pinnate, or 

 furnished with alternate subdistichous or quadrifarious lesser branches, 

 mixed with short tooth-like ramuli. Stem and main branches clumsy, from 

 . two to five lines or more in diameter, more coriaceous than others of the 

 genus. Ultimate branches simple or forked, tapering to an obtuse point ; 

 all the axils rounded. Filaments of the axis loosely interwoven; their 

 joints pear-shaped or cylindrical: — those of the periphery dichotomous, 

 with globular joints; ultimate fibres about five in a cluster, their joints 

 gradually larger from the base upwards, containing granular matter, spores 

 dliptical-obovate, sessile. Colour muddy olive, yellowish, or brow n. 



This species, the best known and earliest described of the 

 genus, as now restricted, appears to have been Hist noticed by 



