PLATE VI. 



Figs. 1-4. — Acaiithella effusa. 



Fig. 1. — Natural size. 



Fig. 2. — Portion of hydrocladium, magnified ; lateral ^^ew. 



Fig. 3. — Same ; front view. 



Fig. 4. — Portion of branch, near its distal end, showing the spine-like appendages carried 

 by every internode, and here replacing the hydrocladia. 



