﻿Amer. 
  Jour. 
  Sci 
  ., 
  Vol. 
  

  

  897. 
  

  

  Plate 
  VI. 
  

  

  m 
  

  

  p 
  

  

  fc 
  

  

  o 
  

  

  

  

  & 
  

  

  

  

  - 
  

  

  -tJ 
  

  

  < 
  

  

  05 
  

  

  

  a 
  

  

  5C 
  

  

  rn 
  

  

  O 
  

  

  c 
  

  

  T3 
  

  

  

  >> 
  

  

  n 
  

  

  rP 
  

  

  

  

  rr> 
  

  

  O 
  

  

  

  

  < 
  

  

  - 
  

  

  p 
  

  

  03 
  

  

  O 
  

  

  OQ 
  

  

  O 
  

  

  

  - 
  

  

  © 
  

  

  c 
  

  

  Sh 
  

  

  a 
  

  

  03 
  

  

  Pm 
  

  

  £ 
  

  

  

  

  

  

  

  o 
  

  

  

  

  

  ^ 
  . 
  

  

  

  

  

  P. 
  -*= 
  

  

  

  s 
  ^ 
  

  

  

  03 
  <D 
  

  

  

  73 
  &■ 
  

  

  

  ■S 
  2 
  

  

  

  O 
  C3 
  

  

  

  £5 
  ft 
  

  

  M 
  

  

  