BULLETIN 59, UNITED STATES NATIONAL MUSEUM. 



45 



Tem,2)erature 60°-60^^' ^'. — Only 7 tonus were ohtaiiiod within thi.s range. 



Temperature 50'- -]fi^ F. — Within these limits 'IV forms wore obtained, a coni- 

 piiratively rich fauna. 



Tt'iiijirratitvi' I^O'-JO' F. — Only 3 species weiv procure*! at a temperature below 

 40° F. 



The greatest abundaiico of forms is ))etween temperatures 73 and 7s , depth 

 U-4() fathoms: a second abundant fauna is between temperatures 70% or somewhat 

 less, and 4ii , or somewhat more, depth 100-400 fathoms. There is a discordance 

 between depth and temperature, for the greatest number of forms at a depth 

 Greater than 4<i fathoms occurs between li>0 and 20t». while the greatest number of 

 forms at a temperature below 70°F. is between 40° and 50^. However, the number 

 between 40= and 50- is nearly the same as between 60*-^ and 73^. It seems from 

 tliese facts that temperatun; l)et\veen 40° and 70'^ is not so important a factor in 

 determining XXw numl)er of the forms or species of corals developed as is the depth. 



Distribution of genera according to ti'inperaiure. 



Total number of genera. 



U 



12 



18 



a Not obtained at a temperatnrt' so high oj? 70*^. 

 b Not obtained at a tcmpfratnre so low a.s 70° 

 c Temperature range doubtful. 



