﻿Chas. 
  D. 
  Walcott, 
  I 
  ~ 
  

  

  U. 
  S. 
  Geol. 
  Survey. 
  

  

  VOL. 
  III. 
  JUNE, 
  1897. 
  

  

  Established 
  by 
  BENJAMIN 
  SILLIMAN 
  in 
  1818. 
  

   THE 
  

  

  AMERICAN 
  

  

  JOURNAL 
  OF 
  SCIENCE. 
  

  

  Editor: 
  EDWARD 
  S. 
  DANA. 
  

  

  ASSOCIATE 
  EDITORS 
  

  

  Professors 
  GEO. 
  L. 
  GOODALE, 
  JOHN 
  TROWBRIDGE, 
  

   II. 
  P. 
  BOWDITCH 
  and 
  W. 
  G. 
  FARLOW, 
  of 
  Cambridge, 
  

  

  Professors 
  O. 
  C. 
  MARSH, 
  A. 
  E. 
  VERRILL 
  and 
  H. 
  S 
  

   WILLIAMS, 
  of 
  New 
  Haven, 
  

  

  Professor 
  GEORGE 
  F. 
  BARKER, 
  of 
  Philadelphia, 
  

   Professor 
  II. 
  A. 
  ROWLAND, 
  of 
  Baltimore, 
  

   Mr. 
  J. 
  S. 
  DILLER, 
  of 
  Washington. 
  

  

  FOURTH 
  SERIES. 
  

   YOL. 
  Ill— 
  [WHOLE 
  NUMBER, 
  CLIIL] 
  

  

  No. 
  18.— 
  JUNE, 
  1897. 
  

  

  NEW 
  HAYEN, 
  CONNECTICUT. 
  

  

  18 
  9 
  7. 
  

  

  TUTTLE, 
  MOREHOUSE 
  & 
  TAYLOR, 
  PRINTERS, 
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  TEMPLE 
  STREET. 
  

  

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