PLATE XY. 
Figs. 1, la . — Lafoea dumosa (p. 34). 
Fig. 1. — A colony; natural size. 
Fig. la.— Portion of a colony; magnified 15 diameters. 
Figs. 2, 2a . — Halecium fastigiatwm (p. 13). 
Fig. 2. — A colony ; natural size. 
Fig. 2a. — Portion of a colony; magnified 15 diameters. 
Figs. 3, 3a . — Hebella striata (p. 30). 
Fig. 3. — Portion of a colony ; natural size. 
Fig. 3a. — Portion of same; magnified 25 diameters. 
