246 FLORA OF MOUNT DESERT. 



E. clathrata (Roth), J. Ag. Ulva clathrata, Farlow's Man- 

 ual, 44. 



In tide pools (Collins); Somes Sound (Holden). 

 E erecta (Lyngb.), J. Ag. 



Resembles E. clathrata, but the cells have more compact and 

 opaque contents, and are less regularly arranged in series. 

 The smaller branches seem articulate, not conferva-like, as in 

 E. Hopkirkii, but after the manner of a Polysiphonia, several 

 cells side by side of the same height. Shore, Little Cranberry 

 Isle (Collins). 



E. Hopkirkii, McCalla. Ulva Hopkirkii, Farlow's Manual, 44. 

 In tide pools, on Cladophora glaucescens, Little Cranberry 

 Isle (Collins). 



MONOSTROMA, Thuret. 

 *M. Blyttii (Aresch.), Wittr. 

 Seal Harbor (Elisa W. Redfield). 



ULVA, L. SEA LETTUCE. 

 TT. lactuca (L.), Le Jolis. 



Occurring in two forms. 

 Var. rigida (Ag.), Le Jolis. 



Common in tide pools and below (Collins). 

 Var. lactuca, Le Jolis. 



Common with the last (Collins). 



SUBDIVISION IV. SCHIZOPHYCEJE. 

 HORMOGONE.E. 



CALOTHRIX, Ag. 

 C. scopuloram (Web. & Mohr), Ag. 



Very common on rocks. Seal Harbor; Little Cranberry Isle 

 (Collins); Sea Wall (Holden). 



