HOW TO KNOW THE SEAWEEDS 

 64b Cells with greatly reticulate or fragmented chloroplasts 65 



65a Filaments attached at the base 



66 



65b Filaments free, floating or entangled 67 



66a Rhizoids, if present, produced only from the basal cell. Fig. 97 . . 

 Chaetomorpha (in part) 



Fig. 97, Chaetomorpha antennina (Bory) Kiitzing 



A. Part of a young plant to show basal attach- 

 ment and presence of rhizoids arising from the 

 basal cell, X 9. B. A portion of a tuft, X 1.5. 

 This is a southern CaUfornia representative of this 

 genus which occurs widely on exposed rocks along 

 both coasts. (See also Fig. 100.) It shows the tufted, 

 gregarious habit of the filaments of the basally at- 

 tached members of this genus of which C. aerea 

 (Dillwyn) Kiitzing is a more widespread but much 

 more slender species. C. melagonium (Weber & 

 Mohr) Kiitzing, from New England, is a similarly 

 coarse species. 



Figure 97 



76 



