196 



JTirst annual IReport 



collection "is a discovery, or rather rediscovery. This species was 

 credited to our coast nearly forty years ago, but so far as I know has 

 not been seen since." 



Calothrix parasitica (Chauv.) Thuret 



(Figure 105) 

 Commonly parasitic in NciiKtlioi/ luliriciiin. 



Calothrix contarenii (Zau) 13. and F. 



Colonies of this species are occasional on exposed rocks almost 

 to high tide mark. 



c 



Figure 106. Chaetomorpha aerea (Dilhv.) Kurtz 



Calothrix fasciculata Ag. 



Colonies common on exposed rocks almost to high tide mark. 

 This and the preceding species form a slippery covering to the 

 rocks that render them very treacherous for the pedestrian. During 

 low tide on a hot day this little alga is seemingly completely dried 

 out, and must be subjected to great heat, but always recovers prompt- 

 ly with the next tide. 



