114 



DESCEIPTION OF PLATE I. 



THE HYDR^, OR FRESH-WATER POLYPES. 

 ( Page 12. ) 



\_The Figures are slightly enlarged, for the sake of distinctness. 1 



Fig. 1. Three Green Polypes, {Hydra viridis), attached to the stem of an 

 aquatic plant, p. 13. 

 a, The base or pedicle of the Hydra. 

 h, The mouth and arms. 

 Fig. 2. The Common Fresh-water Polype, (/Zy^Zra vulgaris), partly con- 

 tracted, and the stomach distended with food. 

 Fig. 3. The Long-armed Polype, {Hydra fused), with the arms extended 

 in search of food, p. 15. 



c, A small red worm seized by one of the tentacula, or arms. 



d. An aquatic insect, caught by another of the arms. 



Fig. 4. The Hydra vulgaris attached to a twig : two young ones are 



seen sprouting from the sides of the body, p. 14. 

 Fig. 5. The Hydra vulgaris in a contracted state. 

 Fig, 6. The Hydra fusca moving to and fro in the water in quest of 



prey, p. 15. 

 Fig. 7. The Hydra fusca, with a worm, which it has partly swallowed ; 



the extremities hanging out of the mouth, and secured by 



the tentacula of the Polype, p. 15. 



