HOW TO KNOW THE SEAWEEDS 



67b Filaments 100-1000 a in diameter, unbranched. Fig. 100 



Chaetomorpha (in part) 



Fig. 100. Chaetomorpha hnum (Miiller) 

 Kiitzing 



A small part of an entangled fila- 

 ment, X 4. One of three free, drifting 

 or entangled species occurring along 

 the Atlantic Coast. Others may be 

 found on Pacific shores of which one 

 of the most striking is the southern 

 CaHfornian C. torta (Farlow) McClatchie 

 which is very coarse (over 1 mm.) and 

 strongly coiled or twisted. 



Figure 100 



68a Color greenish, usually grass green 



69 



68b Color reddish or brownish, not grass green or greenish 71 



69a Lower parts of plants held together by rhizoidal, hooked or spine- 

 like branchlets. Fig. 101 Spongomorpha 



Fig. 101. Spongomorpha spp. 



A. Spongomorpha coahta 

 (Ruprecht) CoUins. The end 

 of a branch showing a hook, 

 X 30. Central CaUfornia and 

 northward. B. Spongomorpha 

 arcta CDillwyn) Kiitzing. A 

 lower part of an axis showing 

 the production of descending, 

 entwining rhizoids, X 30. This 

 plant forms hemispherical tufts 

 on exposed rocks along the 

 New England coast. Several 

 other species occur along the 

 p. ,-,, northern shores of both coasts. 



Figure 101 



78 



