﻿OSTEOLOGY 
  OF 
  TESTUDO 
  PRAEEXTANS 
  — 
  GILMORE 
  307 
  

  

  spociinons 
  all 
  hail 
  i)it)aclly 
  roundtil 
  aiitoiior 
  carapace 
  borders 
  and 
  

   prominent 
  epiplastral 
  lips 
  with 
  parallel 
  sides, 
  as 
  contrasted 
  with 
  the 
  

   more 
  truncate 
  carapace 
  hoidi^r 
  and 
  wedge-shaped 
  epiplastral 
  lip 
  in 
  

   T. 
  lat'ivuiua. 
  

  

  This 
  study 
  of 
  a 
  number 
  of 
  Testudo 
  specimens 
  from 
  a 
  restricted 
  area 
  

   antl 
  apparently 
  of 
  a 
  single 
  species 
  shows 
  enough 
  variation 
  in 
  shell 
  

   structure 
  to 
  cast 
  much 
  doubt 
  on 
  the 
  validity 
  of 
  many 
  described 
  species, 
  

   especially 
  those 
  foundetl 
  on 
  fragmentary 
  materials. 
  Furthermore, 
  it 
  

   raises 
  the 
  perplexing 
  question 
  as 
  to 
  what 
  featvn'es 
  are 
  to 
  be 
  relied 
  on 
  

   for 
  specific 
  difrcrentation. 
  It 
  has 
  been 
  demonstrated 
  (pis. 
  38-41) 
  

   that 
  the 
  neural, 
  costal, 
  and 
  other 
  elements 
  forming 
  the 
  carapace, 
  as 
  

   well 
  as 
  the 
  form 
  and 
  proportions 
  of 
  the 
  vertebral 
  and 
  plastral 
  scutes, 
  

   are 
  seldom 
  in 
  themselves 
  suflicientl}' 
  constant 
  in 
  shape 
  and 
  proportion 
  

   to 
  be 
  relied 
  on 
  for 
  specific 
  designation. 
  

  

  ^^^lether 
  characters 
  of 
  the 
  skull 
  in 
  fossil 
  Testudo 
  will 
  be 
  found 
  more 
  

   stable 
  can 
  only 
  be 
  determined 
  when 
  a 
  series 
  of 
  crania 
  is 
  available 
  for 
  

   comparison, 
  and 
  at 
  this 
  time 
  no 
  such 
  series 
  exists. 
  It 
  is 
  in 
  the 
  general 
  

   form 
  of 
  the 
  carapace 
  and 
  plastron 
  and 
  especially 
  in 
  the 
  development 
  

   of 
  epiplastral 
  beak 
  that 
  most 
  reliance 
  has 
  been 
  placed 
  in 
  diagnosing 
  

   the 
  present 
  species. 
  

  

  TESTUDO 
  LATICUNEA 
  Cope 
  

  

  Plates 
  42, 
  43 
  

  

  Testudo 
  lalicunea 
  Cope, 
  Paleont. 
  Bull. 
  No. 
  15, 
  p. 
  6, 
  1873. 
  — 
  Hay, 
  Carnegie 
  Inst. 
  

   Wa.shington 
  Publ. 
  75, 
  p. 
  402, 
  pi. 
  67, 
  figs. 
  1, 
  2, 
  1908. 
  

  

  Two 
  specimens 
  (U.S.N. 
  M. 
  Nos. 
  15854 
  and 
  16731) 
  in 
  the 
  Oligocene 
  

   collections 
  from 
  eastern 
  Wyoming 
  are 
  identified 
  as 
  pertaining 
  to 
  

   Testudo 
  laticunea 
  Cope, 
  the 
  first 
  recorded 
  occurrence 
  of 
  the 
  species 
  

   in 
  this 
  area. 
  These 
  specimens 
  are 
  remarkably 
  alike 
  (cf. 
  pis. 
  42 
  and 
  

   43) 
  both 
  in 
  size 
  and 
  structural 
  detail, 
  a 
  condition 
  calling 
  for 
  comment, 
  

   as 
  anyone 
  will 
  agree 
  who 
  has 
  had 
  occasion 
  to 
  study 
  a 
  series 
  of 
  Testudo 
  

   specimens. 
  

  

  The 
  type 
  of 
  T. 
  laticunea 
  is 
  an 
  essentially 
  complete 
  shell, 
  with 
  some 
  

   of 
  the 
  internal 
  skeleton, 
  and 
  was 
  found 
  in 
  the 
  Oligocene 
  badlands 
  

   along 
  the 
  head 
  of 
  Horse 
  Tail 
  Creek 
  in 
  northeastern 
  Colorado. 
  Two 
  

   other 
  specimens, 
  one 
  from 
  the 
  Tiianotherium 
  beds 
  (Chadron) 
  of 
  South 
  

   Dakota 
  and 
  one 
  from 
  the 
  Oreodon 
  beds 
  (Brule) 
  of 
  Siou.x 
  County, 
  

   Nebr., 
  were 
  identified 
  by 
  Hay 
  * 
  as 
  jx'rtaining 
  to 
  this 
  species. 
  These 
  

   together 
  with 
  the 
  two 
  in 
  the 
  U. 
  S. 
  National 
  Museum 
  comi)rise 
  all 
  

   the 
  known 
  materials 
  of 
  the 
  .species. 
  

  

  Specimen 
  U.S.N.M. 
  No. 
  15854 
  consists 
  of 
  a 
  nearly 
  complete 
  cara- 
  

   pace 
  and 
  plastron 
  (pi. 
  43), 
  left 
  humerus, 
  proximal 
  end 
  of 
  right 
  ; 
  left 
  

   ulna, 
  radius, 
  and 
  part 
  of 
  forefoot; 
  incom])letc 
  right 
  scai)ula, 
  left 
  

  

  ' 
  Hiiy, 
  o. 
  v., 
  CamoKie 
  Inst. 
  Wa.shlDKlon 
  I'ubl. 
  T.'i, 
  \t\). 
  IOt-40:., 
  1908. 
  

  

  