PLATE VI. 
Figs. 1-4.—Acanthella effusa. ‘ ‘. 
Fig. 1,—Natural size. 
Fig. 2.—Portion of hydrocladium, magnified ; lateral view. 
Fig. 3.—Same ; front view. “6 ‘ : 
se +e us Fig. 4.—Portion of renee near its distal end, showing the spine-hke appendages eared nm 
¥ by every internode, and here replacing the iageeee io 
