CCELENTEEATA. 



253 



Pio. Wl.—iradrepora a^pera, liviDg and expanded ; natural size. Pacific. 



whose mean temperature in tlie coldest month is below 

 68° Fahr., nor at greater depth than twenty fathoms. The 

 most luxuriant reefs are in the Central and Western Pa- 

 cific and around the West Indies. 



Pio. ■m.-aeruKtia echinata, or "Mushroom-coral ;" one fourth natural size. Pacific 



