MESOGLOIA. 47 



tufts, the branches spreading in all directions from a centre ; very irregu- 

 larly divided. Branches mostly forked, with very patent axils. The sur- 

 face is slimy, the colour olive, much paler than in the preceding species, 

 and the filaments of the periphery are of a different form. It shrinks much 

 in drying. 



II. MESOGLOIA. Ag. [Plate 10, B.] 



Frond filiform, much branched, gelatinous: the axis com- 

 posed of longitudinal, sub-simple, interlacing fibres, invested 

 with gelatine ; the periphery formed of radiating, dichoto- 

 mous, coloured filaments. Fructification : ovate or elliptical 

 olivaceous spores, attached to the ramuli of the periphery. 

 Name, (A<ro$, the middle, and -yxcuof, viscid ; from the gelatinous 

 axis. 



1. M. vermicular is, Ag. ; frond clumsy; branches irregu- 

 larly pinnate, thick, worm-like, lineari-fusiform ; ramuli co- 

 pious, long, flexuous, resembling the branches. Hook. Brit. 

 Fl. ii. p. 387. Riv. verm. E. Bot. 1. 1818; Wyatt, Alg. 

 Damn. No. 100; Harv. Phyc. Brit. t. xxxi. 



On rocks and stones between tide-marks, common. Annual. Summer. 

 Fronds 1 2 feet high, gelatinous and flaccid ; the branches clumsy, of 

 unequal diameter, generally much attenuated at each end. Colour pale 

 olive-green or yellowish. Spores ovate, commonly produced. 



2. M. Griffithsiana, Grev. ; frond slender, equal through- 

 out; branches alternate or irregular, filiform, long, simple, 

 nearly bare of ramuli. Hook. Br. Fl. \\..p. 387; Wyatt, Alg. 

 Danm. No. 48. 



Between tide-marks, rare. Annual. Summer. South of England and 

 West of Ireland. Fronds 8 16 inches high, of a rather pale olive-green, 

 which becomes greener in fresh water. Stem sub-simple, beset throughout 

 with very long, slender, simple, opposite or alternate branches ; the surface 

 covered with long colourless fibres, similar to what occur in Chordaria fla- 

 gelliformis, which make the plant, as it waves in the water, look of much 

 greater diameter than it really is. Spores pyriform. 



3. M. virescens, Carm. ; frond filiform, gelatinous ; branches 

 long, erecto-patent, slender, villous ; ramuli numerous, patent, 

 short, flexuous, obtuse. Hook. Br. Fl. ii. p. 387 ; Wyatt, 

 Ala. Danm. No. 49; Berk. GL Alg. t. 17, /. 2; (also M. affi- 

 nis, Berk., and M. gracilis, Carm. ; Berk. I. c. t. 16, 2, and 

 t. 17, 1) ; Harv. Phyc. Brit. t. Ixxxii. 



Sea shores. Annual. Summer. Not uncommon. Fronds 8 12 inches 

 high, olive-green, tender, gelatinous, slippery, excessively branched ; 



