﻿248 
  

  

  G. 
  i?. 
  Weiland 
  — 
  Huge 
  Cretaceous 
  Turtles. 
  

  

  Measurements 
  of 
  the 
  pelvis 
  of 
  Archelon 
  ischyros 
  Weiland 
  (type). 
  

  

  M. 
  

  

  Extreme 
  antero 
  posterior 
  length 
  . 
  _ 
  

  

  Extreme 
  width 
  .. 
  

  

  Width 
  taken 
  across 
  the 
  acetabular 
  surfaces 
  . 
  _ 
  . 
  

  

  Shortest 
  diameter 
  of 
  obturator 
  foramen 
  

  

  Longest 
  diameter 
  of 
  obturator 
  foramen 
  . 
  . 
  

  

  Acetabular 
  width 
  

  

  Acetabular 
  length 
  

  

  f 
  Antero 
  posterior 
  length 
  

  

  | 
  Width, 
  greatest 
  . 
  

  

  p 
  , 
  . 
  J 
  Greatest 
  thickness 
  (acetabular) 
  . 
  . 
  

  

  | 
  Antero-posterior 
  width 
  of 
  entopubis 
  

  

  | 
  Thickness 
  of 
  entopubis 
  (distal) 
  _ 
  

  

  [Thickness 
  of 
  ectopubis 
  (distal) 
  

  

  " 
  Extreme 
  length 
  

  

  " 
  internal 
  width 
  

  

  Ischium^ 
  " 
  external 
  " 
  

  

  | 
  Width 
  at 
  middle 
  of 
  shaft 
  

  

  [ 
  Thickness 
  of 
  " 
  " 
  " 
  

  

  Extreme 
  length 
  . 
  

  

  " 
  width 
  of 
  the 
  acetabular 
  surface 
  . 
  

  

  . 
  Thickness 
  (least) 
  at 
  middle 
  of 
  shaft 
  

  

  j 
  Thickness 
  (greatest) 
  at 
  middle 
  of 
  shaft 
  

  

  J 
  Greatest 
  distal 
  diameter 
  

  

  [Least 
  " 
  " 
  

  

  •79 
  

  

  •81 
  

  

  •46 
  

  

  •05 
  

  

  •08 
  

  

  •12 
  

  

  •14 
  

  

  •46 
  

  

  •405 
  

  

  •175 
  

  

  •25 
  

  

  •07 
  

  

  •04 
  

  

  •14 
  

  

  •15 
  

  

  •10 
  

  

  •06 
  

  

  •033 
  

  

  •30 
  

  

  •093 
  

  

  •046 
  

  

  •105 
  

  

  •095 
  

  

  •06 
  

  

  Archelon 
  Marshii, 
  sp. 
  no 
  v. 
  

  

  A 
  second 
  species 
  of 
  the 
  genus 
  Archelon 
  is 
  indicated 
  by 
  a 
  

   specimen 
  collected 
  by 
  the 
  writer 
  on 
  the 
  east 
  side 
  of 
  the 
  

   Cheyenne 
  River 
  in 
  the 
  Bad 
  Lands 
  proper 
  in 
  August 
  1898. 
  

   Like 
  the 
  others, 
  this 
  specimen 
  was 
  found 
  in 
  the 
  uppermost 
  

   Fort 
  Pierre 
  Cretaceous, 
  just 
  beneath 
  the 
  Miocene 
  or 
  White 
  

   River 
  formation. 
  

  

  It 
  consists 
  in 
  the 
  plastron, 
  humerus, 
  ribs 
  and 
  a 
  number 
  of 
  

   marginals 
  indicating 
  a 
  turtle 
  of 
  great 
  size, 
  probably 
  11 
  feet 
  in 
  

   length. 
  The 
  humerus 
  is 
  rather 
  straighter 
  than 
  in 
  A. 
  ischyros, 
  

   and 
  the 
  plastron 
  is 
  relatively 
  more 
  massive, 
  being 
  fully 
  one 
  

   half 
  thicker 
  than 
  in 
  that 
  species. 
  As 
  a 
  slight 
  token 
  of 
  respect 
  

   this 
  species 
  is 
  named 
  in 
  honor 
  of 
  Professor 
  O. 
  C. 
  Marsh, 
  to 
  

   whose 
  interest 
  the 
  Museum 
  of 
  Yale 
  University 
  is 
  indebted 
  for 
  

   the 
  possession 
  of 
  these 
  gigantic 
  Testudinates. 
  

  

  Position 
  of 
  the 
  Genus 
  Archelon. 
  

  

  While 
  the 
  genus 
  Archelon 
  presents 
  many 
  intermediate 
  

   characters 
  and 
  strongly 
  supports 
  the 
  view 
  that 
  Dermochelys 
  

   belongs 
  to 
  the 
  Orpytodira, 
  as 
  strenuously 
  insisted 
  upon 
  by 
  

  

  