PLATE XVI 





■ f ^ 



Pickerel-Frog (Rana palustris). 



1. An egg-area and one mated pair. 



2. A croaking male showing vocal sac on either side of the head. Flash-light. 



3. A series of pickerel-frogs from tadpole to transformed pickerel-frog. Dorsal aspect. XI. 



