HOW TO KNOW THE SEAWEEDS 



36b Cortical cells not in regular rows; axes without whorls of 2-celled 

 spines. Figs. 60, 61 Ceramiuni (in part) 



Fig. 60. Ceramium pacificum (Collins) Ky- 

 lin 



A very small part of a branch to show 

 the irregular arrangement of the cortical 

 cells over the large, subspherical cells of 

 the axial filament, X 190. A widely dis- 

 tributed species from southern California 

 to Vancouver Island. 







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Figure 60 



Figure 61 



Fig. 61. Ceramium rubrum (Hudson) C. 

 Agardh 



A small upper part of a plant, X 6. 

 This is the largest and commonest of the 

 completely corticated Ceramium species 

 of the Atlantic Coast, occurring from Flori- 

 da to Newfoundland. On the Pacific 

 Coast C. pacificum (Collins) Kylin and C. 

 eatonianum (Farlow) De Toni are similar, 

 while C. codicola J. Agardh is a common 

 epiphyte on Codium. For other, incom- 

 pletely corticated Ceramium species see 

 step 28b and Figs. 43, 45. 



37a Branchlets contracted at the base, 500 



fx or less in diameter. Fig. 62 



Chondria (in part) 



Fig. 62. Chondria sedifolia Harvey 



A small upper part of a tetrasporic 

 plant, X 4. This is the only one of our 

 common Chondria species with depressed 

 apices. Plants reach 10-15 cm. in height 

 and occur along the whole Atlantic Coast 

 to as far north as Massachusetts. 



Figure 62 



57 



