Though named " dislichophylla'' it has little claim, par excel- 

 lence, to this designation ; for, like many distichous CaulerpcB, it 

 is liable to vary to tristichous or irregularly spiral. A slight twist 

 in the growing stem is sufficient to destroy the perfectly dis- 

 tichous character; but besides this, it frequently happens (as 

 shown at Fig. 2), that a ramentum is emitted from the middle 

 region of the rachis, between the two distichous ramenta. Such 

 a circumstance, occurring as it does even more commonly in 

 several other distichous species, teaches us how worthless, as a 

 generic character, the distichous or non- distichous ramentation 

 in Caulerpa is : — yet on this alone it has been proposed to 

 divide the genus. 



Fig. 1. Caulerpa distichophylla, — the natural size. 2. Part of a branch : — 

 maguijled. 



