1920] Allen: Plankton of the San Joaquin River 125 



9. The abundant occurrence of Bacillana paradojca, generally 

 listed as a typical brackish water form, is notable. This seems to be 

 one case in which marked departure from a typical chemical environ- 

 ment has not visibly affected structure or behavior. 



10. Lastly, it is necessary to emphasize the fact again that what- 

 ever fault or error there may be in this report is chargeable absolutely 

 to the writer. In some cases expert advice has not been followed after 

 being asked. On the other hand, there is the deepest obligation to the 

 persons already mentioned for advice and assi.stance. 



ADDENDUM 



Since writing the discussion of the series of plankton collections 

 of 1913 the statistics for the collections of 1914 and 1915 have been 

 compiled and examined. Inasmuch as weekly collections only were 

 taken in 1914 and 1915, and since two stations only were used in each 

 of these years, the records are much less comprehensive than those for 

 1913. On this account, and also because the 1914 and 1915 records 

 are essentially similar to those for 1913, it seems inadvisable to pre- 

 pare them for publication. The collections for 1914 and 1915 have 

 already been deposited with the Department of Zoology of the Uni- 

 versity of California and it is the writer's intention to deposit the 

 manuscript records in the same place. 



Transmitted August 15, 1918. 



