CRYPTOGAMIAl algm. ^59 



It often fwims upon the furface of the water in 

 clufters like a fcum, and looks bloated as if in 

 a ftate of fermentation. Sometimes it is feen 

 under the water in an erefl pdfition, fix'd to 

 the bottom. 



$ompreJfa^. ULVA tubulofa ramofa comprefTa. Syji. nat, 

 edit. 13. p. 817. Sp. pi. 1632. (Dillen. mufc. 

 48. /.p. /. 8. A. B.C. D. E. et tab. 10./. 8. 

 F. G. bon^. Lafcl. Fl. Prujf. p, 172. n. 51. 

 Petiver. Gaz. t. g. f. 6.) 



Thread and Tape Laver. Anglis. 



Upon rocks and ftones on the fea- (bores very 

 common, as alfo upon boards and timber that 

 is wafh'd by the tides, in dock-yards and other 

 places. Limiaus fays it is fometimes found 

 upon thatch'd houfes, but fuch, we prefume he 

 means, as are within the fpray of the fea. 



This fpecies varies jextremely both in fize and 

 figure. Its mofl general appearance is as fol- 

 lows : — Many narrow, very thin, membrana- 

 ceous, fimple, grafs-like leaves grow in a cluf- 

 ter from the fame root, which appear flat and 

 comprefs'd, but if properly examin'd will be 

 found to be tubular, or to confnl of a double 

 membrane. Thefe leaves have a fmooth and 

 equal furface, not fmuated and wrinkled like 

 the preceding J of various fises, from that of fine 



threads 



