﻿Chas 
  D. 
  Walcott, 
  

  

  U. 
  S. 
  Geol. 
  Survey. 
  

  

  F. 
  VOL. 
  yiii. 
  

  

  i 
  

  

  JULY, 
  1899. 
  

  

  Established 
  by 
  BENJAMIN 
  SILLIMAN 
  in 
  1818. 
  

  

  TH'E 
  

  

  AMERICAN 
  

  

  JOURNAL 
  OF 
  SCIENCE 
  

  

  Editor: 
  EDWARD 
  S. 
  DANA. 
  

  

  ASSOCIATE 
  EDITORS 
  

  

  Professors 
  GEO. 
  L. 
  GOODALE, 
  JOHN 
  TROWBRIDGE, 
  

   H. 
  P. 
  BOWDITCH 
  AND 
  W, 
  G. 
  FARLOW, 
  of 
  Cambridge, 
  

  

  Professors 
  A. 
  E. 
  VERRILL, 
  HENRY 
  S. 
  WILLIAMS, 
  and 
  

   L. 
  V. 
  PIRSSON, 
  OP 
  New 
  Haven, 
  

  

  Professor 
  GEORGE 
  F. 
  BARKER, 
  of 
  Philadelphia, 
  

   Professor 
  H. 
  A. 
  ROWLAND, 
  of 
  Baltimore, 
  

   Mr. 
  J. 
  S. 
  DILLER, 
  of 
  Washington. 
  

  

  FOURTH 
  SEEIE§. 
  

   VOL. 
  YIII— 
  [WHOLE 
  NUMBER, 
  CLYIIL] 
  

  

  No. 
  43.— 
  JULY^ 
  1899. 
  

  

  NEW 
  HAYEN, 
  CONNECTICUT. 
  

  

  18 
  99. 
  

  

  TUTTLE, 
  MOREHOUSE 
  & 
  TAYLOR, 
  PRINTERS, 
  125 
  TEMPLE 
  STREET. 
  

  

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