﻿306 
  Mr. 
  D. 
  M. 
  S. 
  Watson 
  on 
  

  

  Pelvic 
  Girdle. 
  

  

  The 
  only 
  new 
  point 
  of 
  interest 
  about 
  the 
  pelvic 
  jyirdle 
  is 
  

   the 
  presence 
  of 
  a 
  thickened 
  bar 
  across 
  the 
  pubes, 
  so 
  that 
  the 
  

   symphysis 
  is 
  suddenly 
  thickened 
  as 
  in 
  Labidosaurus 
  at 
  one 
  

   point. 
  

  

  Comparison 
  ivith 
  V. 
  brevirostris. 
  

  

  The 
  reptile 
  whose 
  structure 
  has 
  just 
  been 
  described 
  differs 
  

   from 
  that 
  described 
  by 
  Williston 
  as 
  Varanosaiirus 
  brevi- 
  

   rostris 
  in 
  a 
  considerable 
  number 
  of 
  characters, 
  Williston 
  

   lias 
  already 
  listed 
  the 
  skulLproportions 
  and 
  the 
  dentition. 
  

   To 
  these 
  we 
  may 
  add 
  : 
  — 
  

  

  IMic 
  holoceplialous 
  ribs. 
  

  

  Tlie 
  flattened 
  and 
  expanded 
  ribs 
  in 
  the 
  pectoral 
  region. 
  

  

  The 
  horizontally 
  placed 
  zyg'apo[)hysial 
  articulating 
  surfaces 
  

  

  and 
  the 
  rather 
  heavier 
  arches 
  of 
  the 
  type 
  species. 
  

   'V\\Q 
  presence 
  of 
  two 
  coracoidal 
  elements 
  in 
  the 
  type. 
  

   Tlie 
  thickening 
  of 
  a 
  part 
  of 
  the 
  pubic 
  symphysis. 
  

   The 
  very 
  probable 
  presence 
  of 
  a 
  complete 
  temporal 
  arcade 
  

  

  in 
  the 
  type. 
  

  

  Williston's 
  animal 
  is, 
  in 
  fact, 
  a 
  more 
  specialized 
  type, 
  

   quite 
  worthy 
  of 
  generic 
  rank. 
  

  

  Comparison 
  luith 
  Dimetrodon, 
  

  

  With 
  fuller 
  knowledge, 
  the 
  skull 
  of 
  Varanosaiirus 
  shows 
  

   many 
  rather 
  unexpected 
  resemblances 
  to 
  that 
  of 
  Dimetrodon. 
  

  

  Comparison 
  of 
  the 
  figures 
  in 
  this 
  paper 
  with 
  those 
  given 
  

   by 
  Case, 
  Broom, 
  and 
  especially 
  fig. 
  44 
  of 
  v. 
  Huene's 
  recent 
  

   paper 
  * 
  will 
  show 
  at 
  once 
  great 
  resemblances 
  in 
  the 
  back 
  of 
  

   the 
  skull 
  and 
  the 
  relations 
  of 
  the 
  interparietal 
  and 
  tabulares, 
  

   and 
  particularly 
  the 
  relation 
  of 
  the 
  supratemporal 
  to 
  the 
  

   parietal, 
  tabular, 
  and 
  squamosal. 
  

  

  The 
  structure 
  of 
  the 
  back 
  of 
  the 
  lower 
  jaw 
  is 
  also 
  very 
  

   similar 
  in 
  the 
  two 
  types. 
  

  

  In 
  fact, 
  there 
  can 
  be 
  no 
  doubt 
  that 
  Broili 
  was 
  perfectly 
  

   correct 
  in 
  his 
  oiiginal 
  idea 
  that 
  Varanosaurus 
  is 
  a 
  Pelyco- 
  

   saur 
  ; 
  there 
  is 
  also 
  no 
  doubt 
  that 
  it 
  is 
  a 
  primitive 
  member 
  of 
  

   that 
  group. 
  In 
  a 
  pa[)er 
  now 
  in 
  the 
  press 
  I 
  have 
  shown, 
  

   following 
  Broom, 
  that 
  the 
  Pelycosaurs 
  are 
  truly 
  members 
  of 
  

   the 
  same 
  great 
  group 
  as 
  tlie 
  South-African 
  Therapsids, 
  

   differing 
  only 
  in 
  the 
  more 
  primitive 
  features 
  of 
  tlie 
  limbs 
  

  

  * 
  JjuU, 
  Anier. 
  Mus. 
  Nat. 
  Hist. 
  vol. 
  xx.vii. 
  art. 
  xviii. 
  p, 
  309, 
  

  

  