^8 Mr. Woodward'/ Obfervaiions upon 



pointed out ; and fome of the acknowledged fuci may undoubtedly 

 be confidered as having their fruiStification fituated in a diaphanous 

 membrane. Having ftated thefe cbjeftions to the prefent generic 

 charader, the following is propofed, not as a perfedl one, but as lefs 

 erroneous, and as better according with the numerous fpecies at 

 prefent arranged under this genus ; and this principally with a view 

 to induce others who are better qualified, to take the matter into 

 confideration, and at length eftablifh one on I'uch fixed and natural 

 principles as may remain |)ermanent, without need of future re- 

 vifion. 



Ulva. 



Char. ejf. Frons membranacca feu gelatinofa, frudificatio (fi 

 adfit) per totam frondem quaquaverfim fparfa. 



Char. nat. Radix nulla nifi bafis frondis paululum explanata. 



Frons continua, fimplex vel ramofa, membranacea 

 feu gelatinofa. 



Fru6lificatio — granula feu femina per totam fron- 

 dem fparfa, folitaria vel congefta, intra fubftantiam 

 vel fub epidcrmide fita. 



The plants belonging to this genus adhere to thefubmarine rocks 

 and ftones, to piles or planks, and not unfrequently to other 

 plants, by an expanded difc, a fmall bulbiform callus, or an un- 

 formed gelatinous lump ; all which are merely the bafe of the frons 

 fomewhat dilated. The frons is either membranaceous or gelati- 

 nous ; the former is either plane or tubulous, and ufually diapha- 

 nous ; the latter either filiform or compreffed, folid or fiftulous, 

 diaphanous or opake. Amongft the membranaceous IJlvce fome 

 are umbilicated, and have not any vifible root, appearing to adhere 



to 



