﻿AND 
  AYES 
  OF 
  NORTH 
  AMERICA. 
  145 
  

  

  LYTOLOMA 
  JEAXESII, 
  Cope, 
  Spec. 
  Nov. 
  

  

  This 
  turtle 
  is 
  known 
  by 
  two 
  marginal 
  bones, 
  the 
  nuchal 
  with 
  its 
  suture 
  for 
  the 
  first 
  vertebral 
  distinct, 
  and 
  the 
  

   first 
  with 
  the 
  usual 
  divergent 
  suture 
  for 
  union 
  with 
  the 
  nuchal. 
  A 
  second 
  specimen, 
  which 
  I 
  owe 
  to 
  the 
  liberality 
  of 
  

   John 
  Meirs, 
  was 
  taken 
  from 
  the 
  lower 
  part 
  of 
  the 
  upper 
  Greensand 
  bed 
  at 
  Hornerstown, 
  Monmouth 
  county, 
  N. 
  J. 
  

  

  It 
  shows 
  its 
  relationship 
  to 
  the 
  Catapleura 
  repanda 
  in 
  the 
  narrow 
  proportions 
  of 
  the 
  nuchal 
  bone, 
  which 
  thus 
  

   resembles 
  an 
  ordinary 
  marginal, 
  and 
  differs 
  entirely 
  from 
  the 
  form 
  in 
  Chelydra 
  and 
  Chelone. 
  Another 
  point 
  of 
  simi- 
  

   larity 
  is 
  the 
  union 
  of 
  this 
  bone 
  with 
  the 
  first 
  marginal 
  by 
  a 
  coarse 
  gomphosis, 
  the 
  process 
  pertaining 
  to 
  the 
  latter. 
  

  

  Its 
  marked 
  peculiarity 
  is 
  the 
  normally 
  narrow 
  and 
  free 
  first, 
  and 
  therefore 
  second 
  marginal 
  bones. 
  The 
  first 
  

   gradually 
  narrows 
  inwardly, 
  and 
  is 
  bordered 
  by 
  a 
  regular, 
  slightly 
  concave, 
  free 
  margin. 
  Its 
  suture 
  with 
  the 
  nuchal 
  

   is 
  straight: 
  its 
  suture 
  with 
  the 
  second 
  has 
  the 
  entering 
  angle 
  near 
  the 
  outer 
  margin 
  seen 
  in 
  C. 
  repanda, 
  P. 
  sopita, 
  

   etc. 
  The 
  rounded 
  margin 
  of 
  the 
  nuchal 
  is 
  not 
  heavy; 
  that 
  of 
  the 
  first 
  marginal 
  is 
  more 
  so 
  than 
  in 
  C. 
  repanda, 
  and 
  

   increases 
  near 
  the 
  posterior 
  suture. 
  

  

  An 
  indistinct 
  scutal 
  suture 
  crosses 
  the 
  middle 
  of 
  the 
  marginal; 
  but 
  whether 
  the 
  marginal 
  scuta 
  are 
  narrower 
  than 
  

   the 
  bone, 
  cannot 
  be 
  determined. 
  The 
  line 
  separating 
  the 
  first 
  vertebral 
  from 
  the 
  nuchal 
  descends, 
  or 
  narrows 
  the 
  

   nuchal 
  scutum, 
  but 
  not 
  so 
  rapidly 
  as 
  in 
  C. 
  repanda, 
  being 
  straight 
  instead 
  of 
  concave. 
  

  

  The 
  first 
  marginal 
  bone 
  is 
  three-fifths 
  as 
  wide 
  as 
  long 
  in 
  the 
  present 
  species 
  ; 
  in 
  the 
  C. 
  repanda 
  four-fifths 
  as 
  wide 
  

   as 
  long. 
  

  

  Lines. 
  

   "Width 
  nuchal 
  marginal, 
  16.5 
  

  

  Width 
  " 
  scutum, 
  8.5 
  

  

  Width 
  first 
  marginal, 
  15.5 
  

  

  The 
  Hornerstown 
  specimen 
  furnishes 
  portions 
  of 
  several 
  costals, 
  and 
  three 
  marginals, 
  with 
  the 
  head 
  of 
  the 
  

   humerus. 
  They 
  were 
  taken 
  by 
  the 
  writer 
  from 
  the 
  green 
  sand, 
  in 
  natural 
  relation; 
  they 
  indicate 
  an 
  animal 
  of 
  as 
  

   large 
  size 
  as 
  the 
  Osteopygis 
  emarginatus, 
  and 
  demonstrate 
  that 
  the 
  characters 
  on 
  which 
  this 
  genus 
  rests, 
  although 
  

   those 
  of 
  immature 
  Osteopyges, 
  are 
  nevertheless 
  those 
  of 
  adult 
  animals. 
  

  

  The 
  superior 
  margin 
  of 
  the 
  first 
  marginal 
  is 
  entire, 
  and 
  rather 
  thin, 
  showing 
  its 
  complete 
  separation 
  from 
  the 
  

   carapacial 
  disc. 
  The 
  outer 
  margin 
  is 
  somewhat 
  thickened, 
  and 
  the 
  proximal 
  extremity 
  exhibits 
  the 
  usual 
  wedge- 
  

   shaped 
  articulation. 
  Length 
  exteriorly, 
  3| 
  in. 
  ; 
  width, 
  1 
  in. 
  5 
  1. 
  A 
  lateral 
  marginal, 
  perhaps 
  the 
  sixth, 
  is 
  remarkable 
  

   for 
  its 
  narrow 
  form, 
  and 
  the 
  nearly 
  equal 
  measurements 
  of 
  the 
  three 
  chords 
  of 
  its 
  transverse 
  section. 
  The 
  external 
  

   face 
  is 
  thus 
  very 
  oblique 
  and 
  the 
  margin 
  not 
  at 
  all 
  recurved, 
  or 
  in 
  any 
  way 
  emarginate. 
  The 
  rib 
  pit 
  is 
  round 
  conic. 
  

   Length, 
  3 
  in. 
  9 
  1.; 
  external 
  face, 
  1 
  in. 
  6 
  lin. 
  wide; 
  internal 
  chord, 
  1 
  in. 
  5 
  1. 
  The 
  inferior 
  and 
  superior 
  inner 
  margins 
  

   are 
  alike 
  thin 
  and 
  acute. 
  Width 
  of 
  a 
  costal 
  bone, 
  3 
  in. 
  G 
  lin; 
  depth 
  near 
  sutural 
  margin, 
  3 
  lines. 
  Diameter 
  humeral 
  

   condyle, 
  1 
  in. 
  6 
  lin. 
  The 
  costal 
  bones 
  are 
  without 
  sculpture. 
  

  

  Discovered 
  in 
  the 
  upper 
  green 
  sand-bed 
  or 
  the 
  upper 
  Cretaceous, 
  near 
  Barnesboro, 
  Gloucester 
  Co., 
  and 
  

   Hornerstown, 
  Monmouth 
  Co., 
  N. 
  J. 
  

  

  This 
  species 
  is 
  named 
  after 
  Joseph 
  Jeanes, 
  of 
  this 
  city, 
  an 
  active 
  and 
  liberal 
  member 
  of 
  the 
  Academy 
  of 
  Natural 
  

   Sciences 
  of 
  Philadelphia. 
  

  

  LYTOLOMA 
  ANGUSTA, 
  Cope. 
  

  

  Chelone 
  sopita, 
  Leidy. 
  Cretac. 
  Rept. 
  U. 
  S. 
  Smithsonian 
  Contrib., 
  XII., 
  p. 
  105 
  (Second 
  Specimen), 
  Tab. 
  

   XIX., 
  fig. 
  2. 
  

  

  Posterior 
  and 
  lateral 
  marginal 
  bones, 
  with 
  the 
  upper 
  margins, 
  not 
  produced 
  beyond 
  the 
  lower. 
  The 
  second 
  with 
  

   a 
  deep, 
  open 
  emargination, 
  the 
  length 
  twice 
  the 
  average 
  breadth. 
  Width 
  of 
  fifth 
  .5 
  length, 
  the 
  superior 
  surface 
  con- 
  

   cave; 
  vertebral 
  scuta 
  wide, 
  angles 
  produced. 
  

  

  This 
  species 
  is 
  at 
  present 
  indicated 
  by 
  a 
  mandible 
  and 
  some 
  marginal 
  and 
  costal 
  bones. 
  These 
  are, 
  however, 
  so 
  

   characteristic 
  and 
  different 
  from 
  anything 
  hitherto 
  observed 
  in 
  the 
  Cretaceous 
  Green 
  Sand 
  of 
  New 
  Jersey 
  as 
  to 
  de- 
  

   AMERI. 
  MILOSO. 
  SOC. 
  YOL 
  XIV. 
  37 
  

  

  