NOTE. 



The 5 parts of volume 23 of the Contributions were issued as follows : 



Part 1, pages 1 to 170, October 11, 1920. 



Part 2, pages 171 to 515, July 14, 1922. '" 



Part 3, pages 517 to 848, July 18, 1923. 



Part 4, pages 849 to 1312, December 31, 1924. 



Part 5, pages 1313 to 1721, November 15, 1926. 



J|@°'The indexes for parts 1 to 4 should be bound with the complete 

 volume, since in the index of part 5 there are reprinted only the 

 generic names of the earlier parts. 



