CONFERVA CHALYBEA. 



C. filamentis pulvinatis, ramofis, tenuHErafe, ftriftis, creftis, faftigiatis ; 

 ramis fub-alternatim fecundis, adfcentibus, obtufis ; arrfcuiis cyliadra- 

 ceis, longis. 



C. chalybea. Roth. Cat. Dot. III. p. 286. Tab. 8. f. 2. 



On Flints in Winterboume Stream at Lewes, Sufl'ex. Wm. Barer, jun. Efq. 



PROFESSOR Mertens firft discovered the prei'ent delicate fpecies in the 

 neighbourhood of Bremen, and communicated it to Dr. Roth, who has 

 publiihed it with a good figure in the third volume of his Catalecta Botanica.— 

 Mr. Borrer has fince added it to the Britifh Flora, having found it in Winter- 

 bourne Stream at Lewes, Suffex, and to him and Mr. Turner I am indebted for 

 the fpecimen here figured. It grows on flint-fines in little tufts about a quarter 

 of an inch in length, and of a blackifh-green color, glofly when dry. The 

 filaments, which are repeatedly branched, are ereQ, ftraight, of equal height, 

 and very flaccid and flender throughout. The branches are placed at uncertain, 

 generally confiderable, diftances from each other; and iflue from the ftem fo as 

 to form an obtuse angle, but immediately curve inwards, and then rife in a more 

 or lefs upright direftion ; their difpofition is far from regular, but they are 

 frequently difpofed on oppofite fides in alternate parcels of two or three. The 

 ramuli are always placed nearer to each other than the main branches, and I 

 have frequently obferved more than one proceeding from the top of the fame 

 joint ; they are blunt at their apices ; the difTepiments are readily obfervable with 

 a microfcope, and divide the filaments into perfeaiy cylindrical joints, of which 

 the length is generally from four to fix times greater than the diameter. 



C. chalybea is mod nearly allied to C. vivipara, but the defection and figure 

 here given will fufficiently prove it diftinft. 

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