﻿U. 
  S. 
  NATIONAL 
  MUSEUM 
  

  

  PROCEEDINGS, 
  VOL. 
  67, 
  ART. 
  4 
  PL. 
  I 
  

  

  m 
  \ 
  

  

  v 
  

  

  N 
  

  

  y 
  

  

  Microscopic 
  Sculpture 
  of 
  Fresh-water 
  Mussels 
  

  

  For 
  explanation 
  of 
  plate 
  see 
  page 
  |3 
  

  

  