Fig. 2. — Potamogeton lucens. 



Fig. I . — Potamogeton natans. 



Fig. 3.- Potamogeton heterophyllus. 



Fig. 4. — Potamogeton lonchites. 



PLATE XXXIV. — WIDE-RANGING SPECIES OF PONDWEEDS. i^From Morong.) 

 (After Biological Survey.) 



