﻿U. 
  S. 
  NATIONAL 
  MUSEUM 
  

  

  PROCEEDINGS, 
  VOL. 
  67, 
  ART. 
  25 
  PL. 
  3 
  

  

  Species 
  of 
  Siphogenerina 
  

  

  For 
  explanation 
  of 
  plate 
  see 
  page 
  23 
  

  

  