HOW TO KNOW THE SEAWEEDS 



58b Thallus regularly or irregularly septate. 



60 



59a Thallus traversed internally by a network of trabeculae. Figs. 

 89, 90, 91 Caulerpa (in part) 



Fig. 91. Caulerpa sp. 



Transection of an axis to show the internal 

 network of trabeculae, X 9. 



Figure 91 



59b Thallus not traversed internally by a network of trabeculae. Fig. 

 92 Bryopsis 



Fig. 92. Bryopsis pennata Lamouroux 



The terminal portion of a young axis, X 

 22. At least four species of this genus are 

 to be found along the. Atlantic coast, two of 

 them (B. hypnoides Lamouroux and B. plumosa 

 (Hudson) C. Agardh) extending as far north 

 as New England. Although no species of 

 Caulerpa is encountered on our Pacific Coast, 

 several kinds of Bryopsis may be found there 

 including the two New England species men- 

 tioned above. Both pinnate and multifari- 

 ous branching occur in the genus. 



Figure 92 



60a Branching radially symmetrical; branchlets whorled 61 



73 



iy 



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