﻿AND 
  AVES 
  OF 
  NOKTH 
  AMERICA. 
  

  

  41 
  

  

  oliasaurus, 
  the 
  supposed 
  caudals 
  of 
  the 
  latter 
  proving 
  to 
  be 
  its 
  cervicals. 
  Characters 
  dis- 
  

   tinguishing 
  it 
  from 
  Plesiosaurus 
  have 
  never 
  been 
  pointed 
  out, 
  and 
  it 
  is 
  here 
  retained 
  apart 
  

   from 
  it 
  on 
  the 
  supposition 
  that 
  its 
  scapular 
  arch 
  is 
  constructed 
  on 
  the 
  same 
  principle 
  as 
  

   that 
  of 
  Elasmosaurus, 
  a 
  point, 
  however, 
  which 
  has 
  not 
  been 
  ascertained. 
  

  

  This 
  genus 
  is 
  not 
  as 
  well 
  known 
  as 
  Elasmosaurus, 
  owing 
  to 
  the 
  fragmentary 
  condition 
  

   in 
  which 
  it 
  is 
  usually 
  found. 
  Its 
  marked 
  character 
  is 
  its 
  short 
  depressed 
  cervical 
  region, 
  

   as 
  compared 
  with 
  the 
  excessively 
  long 
  and 
  compressed 
  one 
  of 
  Elasmosaurus. 
  It 
  also 
  dif- 
  

   fers 
  from 
  it 
  in 
  the 
  apparent 
  continuity 
  of 
  the 
  series 
  of 
  diapophyses 
  from 
  the 
  dorsal 
  to 
  the 
  

   cervical 
  series. 
  In 
  Elasmosaurus 
  these 
  processes 
  are 
  wanting 
  on 
  the 
  anterior 
  dorsals. 
  

   They 
  are 
  very 
  elongate 
  on 
  the 
  other 
  hand, 
  on 
  the 
  posterior 
  dorsals 
  of 
  Elasmosaurus 
  ; 
  in 
  

   Cimoliasaurus 
  we 
  have 
  as 
  yet 
  no 
  evidence 
  as 
  to 
  their 
  length, 
  as 
  they 
  are 
  broken 
  in 
  our 
  

  

  specimens. 
  

  

  Fig. 
  13. 
  

  

  Fiar. 
  14. 
  

  

  Fig. 
  1G. 
  

  

  Fig. 
  15. 
  

  

  The 
  rapid 
  diminution 
  in 
  dimensions 
  of 
  the 
  cervical 
  series 
  in 
  Cimoliasaurus 
  indicates 
  

   a 
  short 
  neck, 
  and 
  far 
  less 
  slender 
  general 
  form. 
  Leidy 
  suggests 
  from 
  the 
  absence 
  

   of 
  sacral 
  characters, 
  that 
  posterior 
  limbs 
  have 
  been 
  probably 
  wanting 
  in 
  this 
  genus 
  : 
  the 
  

   same 
  vertebral 
  characters 
  are 
  seen 
  in 
  Elasmosaurus, 
  but 
  it 
  has 
  a 
  large 
  pelvic 
  and 
  scapular 
  

   arches 
  ; 
  the 
  presence 
  of 
  limbs 
  in 
  it 
  cannot 
  be 
  doubted. 
  The 
  femur 
  of 
  Cimoliasaurus 
  is 
  

   described 
  below, 
  and 
  is 
  the 
  only 
  limb 
  bone 
  yet 
  assignable 
  to 
  a 
  species 
  of 
  this 
  genus. 
  It 
  

   resembles 
  that 
  of 
  Plesiosaurus. 
  It 
  is 
  thicker 
  and 
  shorter 
  however 
  than 
  in 
  any 
  species 
  of 
  

   the 
  latter 
  genus, 
  and 
  is 
  quite 
  short. 
  The 
  distal 
  extremity 
  is 
  thick, 
  and 
  presents 
  pits 
  for 
  

   the 
  attachment 
  of 
  the 
  articular 
  cartilage; 
  the 
  faces 
  for 
  both 
  ulna 
  and 
  radius 
  are 
  extensive, 
  

   and 
  indicate 
  a 
  large 
  manus 
  and 
  elongate 
  limb. 
  The 
  rotundity 
  of 
  the 
  head 
  indicates 
  ex- 
  

   tensive 
  rotation 
  ; 
  and 
  we 
  may 
  be 
  satisfied 
  that 
  the 
  animals 
  of 
  this 
  genus 
  were 
  furnished 
  

  

  AMERI. 
  PHILOSO. 
  SOC. 
  — 
  VOT>. 
  XIV. 
  11 
  

  

  