238 



ANIMALS OF LAND AND SEA 



The brilliant phosphorescence given out by sea-pens and 

 related forms living on the bottom in deep water has already 

 been described. Mr. Agassiz has noted that in the Caribbean 





Figs. 686-695. Hydroids, a Siphonophore, and Sponges. 

 For explanations of the figures see p. xxxiii. 



several sorts of gorgonians and of antipatharians showed a 

 bright bluish light as they came up in the trawl. These plant- 

 like things growing on the bottom are among the most brilliant 

 and most beautiful of all the phosphorescent animals. A few 



