CONFERVA MUTABILIS. 



C. filaraentis ramofiffirnis gelatinofis fub-moniliformibus ; ramulis peni- 

 cilliformibus, fetaceis, ramofis ; diffepimentis contracts, articulis 

 brevibus. 



C. mutabilis. Roth Cat. Bot. I. p. 197. 

 C. gelatinofa, y. Fl. Ang. p. 598. With. IV. p. 135. 



Conferva ' efpece non decrite.' Vaucher in Journal de Phyfique, LII. t. 3. f. 7. 

 C. ftagnalis, globulis virefcentibus mucofis. Dill. Mufc. p. 38. t. 7. f. 44. 

 In Ditches and Rivulets adhering to Sticks, Stones, or decaying Vegetable*; 

 about London and Yarmouth, common. 



IT is fufficiently known that five of the Conferva? nodofaj, which Dillenius in 

 his Hill. Mufc. defcribed as diftinft, were afterwards united by Linnaeus in the 

 Spec. Plant, into a fingle fpecies, under the name of C. gelatinofa. Of thefe, the 

 firft, fecond, and fourth, though fubmitted to a microfcope, exhibit no farther 

 difference than that of colour. The fifth is C. atra, figured in the preceeding plate; 

 and the third, which is the plant now before me, even if but nightly magnified, 

 inftead of the fhort crowded verticillated ramuli., which occafion the charatteriftic 

 bead-like appearance of C. gelatinofa, arrefts the attention of the obferver by its 

 delicate pellucid almoft colourlefs fhoots, befet on each fide by a number of very 

 minute green tufts of ramuli, difpofed generally in oppofite directions. Dr. Roth 

 feems to have been the earlieft among modern botanifts who accurately afcertained 

 its nature, and he publiftied it with a well-defined character in the firft fafciculus 

 of his Cataletta Botanica, giving to it the name of mutabilis, on account of a very 

 fingular change that he obferved it undergo, in different periods of its exiftence. — 

 He has erred in referring, as a fynonym to Dillenius, ' C. fluviatilis fericea tenuis,' 

 t. 6. f. 34 ; but his miftake is by no means furprifing ; for that figure not badly 

 expreffes the general habit of the plant ; and the etching above referred to, which 



