496 



BUI.I.BT1N OF THE BUREAU OF FISHERIES. 



Average Number of Genera and Species of Plants Taken Upon Bottoms of "Gravel and 



Stones/' Division B (167 Stations). 



Groups. 



Species. 



ChlorophycesE . 

 Phaeophyceae . 

 Rhodophyceae. 

 Zostera marina 



0.09 



1-3 



6.0 



Average Number of Genera and Species of Plants Taken Upon Bottoms of "Mud," Division 



C (112 Stations). 



Groups. 



Species. 



Cyanophyceae . 

 Chlorophycese. 

 Phaeophyceae . , 

 RhodophycesE. 

 2^tera marina 



Species Dredged at One-fourth or More of the Stations. 

 [The figures at the top oi the columns represent one-fourth of the total number of stations in each group.] 



