M SSA AfOSSES. 



well to paper, and is, by far, the uu' i ncautiful and 

 most rrumngcablc of our 6%'<r, for the hcrl)arium. 



Ulva lactuca,* I^ 



The full gro^Ti plant differs from the pol>Tnoq>hus 

 iatissima, which it in most respects, much resembles, 

 chiefly in these two particulars. It is of a paler color, 



• 



and a much thinner sul>stance. On di&section, it is 

 found to consist of but one byer of cells, * while U, 

 iattissima has two layers. This (act, no doubt, accounts 

 for lK>th the peculiarities named above. When young, 

 it - - -^id to fonn an inflated bog like an overgrown 

 I\nUt\?morpha intestinalis^ then at length by splitting 

 along the side, floats out a thin membrane of but 

 one liyer of ceUs. It b an annual, and a|»pc.irs 

 in si>nng and summer along with, Init not so com- 

 mon as U. httissima, 1 found it in .August, very 

 pleniiful and very large at Souihold, L. I. 



Ulva fasciata, f Deulx. 



-p .' rr..T.,i 1^ niore rigid even than that of U* 

 La 111, i una ^ tiM:^ £rora a short stem, and is divided into 

 several strap-shaped segments half to three-fourths of 

 an inch wide, of nearly equal breadth throughout, and six 



t Fmosu » b. 



