77 



CALOTHRIX, Thuret. 



0. confervicola, Ag. 



Parasitic on various algae at Brant Point. 

 C. Crustacea, Born & Thur. 



Color bright green, distinguishing it from the preceding spe- 

 cies, which is blackish. Found with the preceding and at 

 Polpis . 



RIVULARIA, Roth. 



R. atra, Roth. 



On shells in harbor. 



IBACTIS, Thuret. 



1. plana, Thuret. 



On shells, etc., Polpis. 



ZOOSPORE^. 



MONOSTROMA, Wietr. 



M. crepidinum, Farlow. 



Resembles a small Ulva Lactuca, but is softer and more deli- 

 cate, and of a very rich deep green color. Wharves in har- 

 bor ; not common. 



ULVA, Le Jolis. 



U. Lactuca, Le Jolis. SEA LETTUCE. 



U. Lactuca, var. latissima, Le Jolis. 

 Species and variety both very common. 



U. enteromorpha, Le Jolis. 

 var. intestinalis. Le Jolis. 

 var. compressa, Le Jolis. 

 Very common in both varieties. 



[NOTE. There is no type of this species distinct from the va- 

 rieties. In all other cases in this list the opposite is the fact, 

 and when, as in Punctaria latifolia, var. Zosterw, a variety 

 only is mentioned, it indicates that although there exists a 

 species distinct from the variety, the latter only has been 

 found on the island shores.] 

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