See. MELANOSPERME^. ( 113 ) Fam. CHORDARIEJ:. 



MESOGLOIA GRIFFITHSIANA.— G^r 



ev. 



Gen. Char.— Frond gelatinous, filiform, subcylindrical, much and irregularly branched, 

 of two strata of cells ; those of the axis arranged in longitudinal filamentous 

 series ; those of the periphery forming vertical, dichotomous, monlliform series ; 

 those at the apices clustered, frequently club-shaped, simple, moniliform. Fructi- 

 fication : ohovate spores attached near the base of the apical fibres. Name from 

 fxecTos, " the middle," and y\oihs, "viscid," alluding to the very gelatinous nature 

 of the fronds. 



Mbsogloia Griffithsiana. — Frond slender, equal throughout ; branches 

 alternate or irregular, filiform, long, simple, nearly bare of ramuli. — Phyc. 

 Brit. 



Mesooloia Griffithsiana.— Grev. MS. ; Eooh. Br. Fl. vol. ii. p. 387 ; Wyatt, Alg. 

 Danm. No. 48 ; Kutz. Sp. Alg. p. 545 ; Earv. P. B. plate 318 ; 

 Earv. Man. p. 47 ; Earv. Syn. p. 41 ; Atlas, plate 14, fig. 56 ; 

 /. G. Agardh, Sp. Gen. Alg. vol. i. p. 57. 



Hab. — In rock-pools between tide-marks, rare. Annual. Summer. Torbay {Mrs. 

 Griffiths) ; Sidmouth {Miss Cutler) ; Roundstone {Mr. M'Calla). 



Geogr. Dist. — Atlantic shores of Europe. 



Description. — Root, a minute disc. Frond cylindrical throughout, 

 very much branched from near the base ; branches sjireading, scarcely 

 attenuated, long and slender ; ramuli few or none, short, simple, patent 

 or divaricate, often a mere tubercle or spine, rarely again branched or 

 forked. Main stem generally simple, six inches to a foot in length, and 

 from half a line to a line in diameter ; all the apices obtuse. The 

 structure of this seems much less dense, and the substance much 

 more gelatinous than that of the other species of the genus ; the tufted 

 filaments of the periphery forming a larger proportion of the diameter. 

 The stem is either partially tubular or becomes so in age by the 

 prematm-e decay of its axil cells. Colour, " a rather pale olive green, 

 becoming greener in fresh water." When the plant is in a growing 

 state, it is clothed with colom'less horizontal fibres, spreading fi-om every 

 portion of the stem and branches, and making them look, when seen 

 under water, of much gi-eater diameter than they really are. 



With this species we are very imperfectly acquainted ; we have never 

 seen it in the living state, and its stnictm-e and substance are too 

 delicate and tender to admit of being revived after being dried so as 

 to show with any satisfactory distinctness its structural characters. 



VOL. III. Q 



