234 ALGjE CHLOROSPERME/E. [Rivularia. 



Pools and ditches. About Limerick, &c. 



2. V. velutina, Ag. Velvet Vauchvia. Filaments creeping; 

 branches erect, fastigiate, woven into a velvetty stratum ; cap- 

 sules solitary, lateral. Carm. Hook. Br. Fl. v. ii. p. 319. 



On the muddy sea-shore. At Miltown Malbay. 



3. V. Dillwynii, Ag. Dillwyrfs Vaucheria. Fronds 

 branched, flexuose ; vesicles globose, lateral, sessile. Hook. Br. 

 Fl. v. u.p.320.Conf.frigida, Dillw. t. 16. 



On the ground, in damp places, common. 



4. V. terrestris, D C. Ground Vaucheria. Filaments 

 straight, forming a lax, somewhat bristly stratum (upon the 

 ground) ; vesicles lateral, hemisphserical on the side of the horn- 

 shaped peduncle or receptacle. Grev. Hook. Br. Fl. v. ii. 

 p. 320. 



On the ground, in moist shady places. 



* * Vesicles two or more together. 



5. V. ccespitosa, Ag. Tufted Vaucheria. Filaments caespi- 

 tose ; branches secund, fructiferous at the apex ; vesicles ses- 

 sile, globose, intermediate horn-shaped, process straight or 

 curved. Carm. Hook. Br. Fl. v. ii. p. 32 1 . Conf. amphibia, 

 Dillw. t. 41. 



On damp earth, or by the side of ditches, &c. 



TRIBE XIX. OSCILLATORIE^. 



Plants growing in the sea, in fresh water, or on damp ground, 

 of a gelatinous substance and filamentous structure. Filaments 

 slender, tabular, continuous, filled with a coloured, granular, trans- 

 versely striate matter, seldom branched, though often agglutinated 

 together so as to appear branched, usually massed together in broad, 

 floating, or sessile strata of a very gelatinous nature ; occasionally 

 erect and tufted, and still more rarely collected into radiating series, 

 bound together by firm gelatine, and then forming globose, lobed, or 

 plane-crustaceoiLS fronds. Fructification : an internal mass, di- 

 vided by transverse septa, finally separating into roundish or lenti- 

 cular sporidia. 



70. RIVULARIA. Roth. Rivularia. 



Frond globose or lobed, rarely incrusting, green or olivaceous, 

 carnose or gelatinous, composed of continuous filaments, an- 

 nulated within, and surrounded by, or set in, gelatine. 

 Name, in allusion to the habitat of some of the species. 



