13° 



FIRST LESSONS IN ZOOLOGY 



but the elongated, circular, ring-shaped, and crescent 

 forms predominate. In the Atlantic Ocean they are 

 found along the coasts of Southern Florida, Brazil, and 

 the West Indies; in the Pacific and Indian oceans there 



Fig, 02. — View of a corul reef off the coast of I'.razil (in^ar liahia); jihuto- 

 graph taken at low tide with the coral projecting just above tlie surface 

 (PhotoL^raph by J. C. Ilraiiuer. ) 



are great coral reefs on the coasts of Australia, Madagas- 

 car, and elsewhere; and certain large groups of inhabited 

 islands, as the Fiji, Society, and Friendly Islands are 

 almost exclusively of coral formation. 



There are over 2000 kinds of coral polyps known, and 

 their skeletons vary much in appearance (fig. 93). Be- 

 cause of the suggestive appearance of some of these they 

 have received common names, as the organ-])ipc coral, 

 brain coral, etc. The red coral of which jewelry is made 

 grows chiefly in the Mediterranean Sea. It is gathered 



