﻿Geology. 
  237 
  

  

  Nat. 
  Mus, 
  Bull. 
  89. 
  Pp. 
  136, 
  37 
  pis., 
  73 
  text 
  figs., 
  1914. 
  A 
  

   Newly 
  mounted 
  Skeleton 
  of 
  the 
  Armored 
  Dinosaur, 
  Stegosaurus 
  

   stenops, 
  in 
  the 
  U. 
  S. 
  National 
  Museum; 
  U. 
  S. 
  Nat. 
  Mus., 
  Proc, 
  54. 
  

   Pp. 
  383-390, 
  pis. 
  57-63, 
  1918.— 
  Two 
  papers 
  by 
  C. 
  W. 
  Gilmore, 
  

   cue 
  of 
  which 
  has 
  just 
  come 
  to 
  haud, 
  amplify 
  our 
  knowledge 
  of 
  

   this 
  remarkable 
  group 
  of 
  dinosaurs 
  in 
  large 
  degree. 
  In 
  the 
  

   larger 
  monograph, 
  Gilmore 
  discusses 
  the 
  following 
  topics 
  : 
  Occur- 
  

   rence 
  and 
  history, 
  wherein 
  he 
  tells 
  of 
  the 
  localities 
  in 
  Como 
  

   Bluff, 
  Wyoming, 
  especially 
  the 
  so-called 
  "Quarry 
  13," 
  together 
  

   with 
  the 
  associated 
  fauna. 
  The 
  second 
  section, 
  consisting 
  of 
  

   about 
  75 
  pages, 
  discusses 
  the 
  osteology 
  of 
  the 
  skeleton, 
  placing 
  

   a 
  modified 
  and 
  more 
  accurate 
  interpretation 
  on 
  the 
  cranial 
  ele- 
  

   ments. 
  The 
  hyoid 
  elements, 
  thus 
  far 
  unknown, 
  are 
  also 
  described 
  

   and 
  figured. 
  Of 
  the 
  vertebral 
  column, 
  a 
  very 
  adequate 
  descrip- 
  

   tion 
  is 
  given, 
  but 
  little 
  of 
  novel 
  character 
  is 
  mentioned. 
  Sternal 
  

   elements 
  are 
  also 
  described 
  and 
  figured 
  for 
  the 
  first 
  time. 
  They 
  

   are 
  paired, 
  and 
  while 
  not 
  so 
  slender, 
  are 
  in 
  a 
  way 
  suggestive 
  of 
  

   the 
  already 
  known, 
  similar 
  elements 
  in 
  Trachodon. 
  The 
  feet 
  

   show 
  resemblances 
  to 
  those 
  of 
  the 
  Sauropoda 
  in 
  the 
  short, 
  robust 
  

   form 
  of 
  the 
  metapodials 
  and, 
  in 
  the 
  manus, 
  the 
  reduction 
  of 
  

   unguals 
  to 
  one 
  or 
  two 
  — 
  those 
  borne 
  on 
  the 
  first 
  two 
  digits. 
  They 
  

   are 
  of 
  course 
  depressed, 
  as 
  with 
  other 
  Ornithopoda, 
  instead 
  of 
  

   being 
  claw-like, 
  but 
  are 
  nevertheless 
  possibly 
  indicative 
  of 
  com- 
  

   munity 
  of 
  habit 
  in 
  the 
  use 
  of 
  the 
  fore 
  limb. 
  The 
  foot 
  is 
  three- 
  

   toed, 
  all 
  of 
  the 
  digits 
  bearing 
  unguals. 
  

  

  The 
  dermal 
  armor 
  is 
  the 
  most 
  characteristic 
  stegosaurian 
  fea- 
  

   ture. 
  In 
  the 
  interpretation 
  of 
  the 
  elements 
  and 
  their 
  mor- 
  

   phology, 
  Gilmore 
  agrees 
  with 
  his 
  predecessors, 
  Marsh, 
  Lucas, 
  and 
  

   Lull, 
  but 
  not 
  in 
  their 
  number 
  and 
  arrangement. 
  Of 
  the 
  flat 
  

   plates, 
  Marsh 
  showed 
  twelve 
  in 
  a 
  single 
  row; 
  Lucas, 
  in 
  two 
  

   restorations, 
  twenty-four 
  and 
  twenty-two, 
  the 
  former 
  in 
  opposing 
  

   pairs, 
  the 
  latter 
  alternating; 
  while 
  Lull 
  in 
  the 
  mounting 
  of 
  

   Stegosaurus 
  ungulatus 
  at 
  Yale 
  showed 
  twenty-eight 
  arranged 
  in 
  

   pairs, 
  with 
  four 
  pairs 
  of 
  terminal 
  caudal 
  spines. 
  Gilmore 
  

   demonstrates 
  pretty 
  conclusively 
  that 
  in 
  S 
  .^stenops, 
  at 
  least, 
  there 
  

   were 
  but 
  twenty 
  alternating 
  flat 
  plates, 
  the 
  largest 
  of 
  which 
  was 
  

   situated 
  over 
  the 
  base 
  of 
  the 
  tail, 
  while 
  the 
  terminus 
  of 
  the 
  latter 
  

   bore 
  but 
  two 
  pairs 
  of 
  spines, 
  and 
  such 
  arrangement 
  must 
  be 
  

   taken 
  as 
  authoritative 
  until 
  disproved. 
  

  

  Following 
  the 
  morphological 
  portion 
  is 
  a 
  taxonomic 
  section 
  in 
  

   which 
  the 
  genera 
  and 
  species 
  of 
  armored 
  dinosaurs, 
  of 
  which 
  the 
  

   types 
  are 
  included 
  in 
  the 
  United 
  States 
  National 
  Museum 
  collec- 
  

   tions, 
  are 
  redescribed. 
  They 
  are: 
  

  

  Stegosaurus 
  stenops 
  Marsh 
  

   Stegosaurus 
  sulcatus 
  Marsh 
  

   Stegosaurus 
  longispinus, 
  n. 
  sp. 
  

   Hoplitosaurus 
  marshi 
  Lucas 
  

  

  