49 



**' conjugate, f 



34. nitin'a. C. fills fimplicibus, demum conjugates, atro viridibus, fplendenter 

 lubricis ; granulis in fpiras plures, ardlas, difpofitis ; articulis diametrum 

 longitudine fub-xquantibus. T. 4. f. C. 



C. nhida. Fl. Dan. t. 819, and C.jugalis, t. 883. 



Conjugata princeps. Vaucher. Hijf.des Con/, d'eau douce, p. 64. t. 4. 



35. dtcimina. C. falls fimplicibus, demum conjugates viridibus, fplendenter 

 lubricis; granulis in fpiras duas laxas difpofitis; articulis diametro fex- 

 duplo longioribus. 



C. decimina. MuLLER in Nova Acla Petrop. III. p. 94. t. 2. 



C. nltida. T. 4. f. A.B. and C.jugalis, T. 5. 



C.fftiformis (3. Roth. Cat. Bot. and FL Germ. 



It will be immediately perceived that the fpecific characters which fepa- 

 rate this fpecies from the foregoing, lie in the different lengths of their 

 joints, the very diffirnilar arrangement of their fpires, and the dark almoft 

 black green of the one contrafted with the paler hue of the other. In both 

 thefe fpecies, Mr. Turner and myfelf have obferved that the granules are 

 fometimes found, either from peculiarity of fituation or from difeafe, fcat- 

 tered irregularly all over the joints, inftead of prefcrving their natural 

 fpiral difpofition ; and in fome individuals there are no traces of thefe what- 

 ever, though at the fame time there is no appearance of their ever having 

 been conjugated. 



36. longata. C. filis fimplicibus, demum conjugatis, flavo-virentibus, lubricis; 

 granulis in fpiram unicam laxam difpofitis ; articulis diametro quadruple 

 longioribus. 



■)• In this divifion are comprifed the Conferva; referred by Vaucher to his genus Crmjugata, a par- 

 ticularly natural and interefting family, which I have described in my Introduction, p. 17. I am 

 forry that I cannot follow this excellent Botanift in adopting all the fpecies which he has defcribed, 

 but I have been led by my own obfervations to divide C. nitida, C. tfiiralit, and C.bijuinctata each into 

 two feparate fpecies, in doing which I hope I have been correct, though I am far from feeling cer- 

 tain on the fu'.ijuct. 



