Tank No. 20. 
25 
fission and budding and form thus, just as the corals 
smaller colonies. At fixed periods they produce buds, 
from the colony and swim about as Me¬ 
dusae,. These again lay eggs, which 
give rise to new Polypes. 
The Hydroid-polypes are found in 
enormous masses on stones, reefs, and 
rocky coasts among the sea-weeds. The 
animals, which form these colonies, live 
on the smallest Crustacea, worms, in¬ 
fusoria etc., which come within reach 
of their tentacles and are stunned by the 
action of the stinging cells. 
SIPH0N0PH0RA. 
(Tank No. 20.) 
These, among the most wonderful of 
the inhabitants of the sea, are at once the 
do, 
which 
larger or 
separate 
Fig. 28. Physophora hydro - Fig. 30. Hip- 
stotica , Y 2 nat. size. popodius nea- 
politanus. 
Fig. 31. Velella spirans. 
Fig. 29. Forskalia contorta. 
