﻿182 
  THE 
  EXTINCT 
  BATRACHIA, 
  REPTILIA 
  

  

  © 
  

  

  another 
  species 
  of 
  Mosasaurus, 
  and 
  from 
  one 
  of 
  Clidastes, 
  as 
  entirely 
  confirmatory 
  of 
  it. 
  

   On 
  the 
  other 
  hand, 
  I 
  am 
  unable 
  to 
  assign 
  hind 
  limbs 
  to 
  any 
  of 
  the 
  species 
  of 
  the 
  order. 
  

   The 
  anterior 
  limbs 
  combine 
  the 
  characters 
  of 
  Testudinata 
  and 
  Sauropterygia. 
  The 
  ulna 
  

   and 
  radius, 
  and 
  all 
  more 
  distal 
  portions 
  of 
  the 
  limbs, 
  are 
  those 
  of 
  the 
  latter 
  order. 
  The 
  

   large 
  ovoid 
  flat 
  carpals, 
  and 
  flat, 
  medially 
  contracted 
  phalanges, 
  with 
  fixed 
  articulations, 
  

   are 
  of 
  that 
  type. 
  Three 
  of 
  such 
  phalanges 
  have 
  been 
  figured 
  by 
  Leidy, 
  Cret. 
  Rept, 
  VIII, 
  

   figs. 
  6 
  and 
  7, 
  where 
  they 
  are 
  regarded 
  as 
  radii, 
  and 
  at 
  fig. 
  13, 
  PL 
  XVII. 
  Ulna 
  and 
  ra- 
  

   dius 
  are 
  figured 
  PI. 
  VIII, 
  figs. 
  9 
  and 
  10. 
  

  

  From 
  the 
  preceding 
  evidence, 
  we 
  may 
  look 
  upon 
  the 
  Mosasauroids 
  and 
  their 
  allies 
  as 
  

   a 
  race 
  of 
  gigantic 
  marine 
  serpent-like 
  Reptiles, 
  with 
  powers 
  of 
  swimming 
  and 
  running 
  

   like 
  the 
  modern 
  Ophidia. 
  Adding 
  a 
  pair 
  of 
  short 
  anterior 
  paddles, 
  they 
  are 
  not 
  badly 
  

   represented 
  by 
  old 
  Pontoppidan's 
  figure 
  of 
  his 
  sea 
  serpent. 
  

  

  That 
  their 
  habit 
  was 
  to 
  devour 
  whole 
  is 
  evident, 
  and 
  though 
  the 
  articulation 
  of 
  the 
  

   lower 
  jaw 
  will 
  not 
  admit 
  of 
  as 
  much 
  extension 
  as 
  that 
  of 
  the 
  Ophidia, 
  it 
  exceeds 
  other 
  

   reptiles 
  in 
  this 
  capacity, 
  allowing 
  by 
  its 
  lateral 
  flexure, 
  of 
  the 
  passage 
  of 
  large 
  objects 
  be- 
  

   tween 
  the 
  rami. 
  The 
  carnivorous 
  Dinosaur 
  on 
  the 
  other 
  hand, 
  tore 
  his 
  prey 
  to 
  pieces, 
  as 
  

   do 
  Mammals 
  of 
  the 
  present 
  day. 
  

  

  Thus 
  in 
  the 
  Mosasauroids 
  we 
  almost 
  realize 
  the 
  fictions 
  of 
  snake-like 
  dragons 
  and 
  sea 
  

   serpents, 
  in 
  which 
  men 
  have 
  been 
  ever 
  prone 
  to 
  indulge. 
  On 
  account 
  of 
  the 
  Ophidian 
  

   part 
  of 
  their 
  affinities, 
  I 
  have 
  called 
  this 
  order 
  the 
  Pythonomorpha. 
  

  

  The 
  families 
  embraced 
  are 
  two, 
  the 
  Mosasauridse 
  and 
  Clidastida?, 
  which 
  differ 
  as 
  

   follows 
  : 
  

  

  Vertebra? 
  with 
  zygosphenal 
  articulation 
  wanting 
  or 
  rudimental 
  ; 
  humerus 
  free 
  in 
  life. 
  

  

  MOSASAURID^E. 
  

  

  Vertebra? 
  with 
  zygosphenal 
  articulation 
  developed 
  ; 
  humerus 
  probably 
  included 
  in 
  

  

  life. 
  CLIDASTID.E. 
  

  

  In 
  time 
  they 
  immediately 
  preceded 
  the 
  Eocene 
  Palaeophides, 
  and 
  probably 
  will 
  find 
  

   in 
  them 
  distant 
  structural 
  allies. 
  

  

  I 
  think 
  it 
  highly 
  probable 
  that 
  the 
  genus 
  Saurosponclylus 
  of 
  Seeley, 
  from 
  the 
  lower 
  

   chalk 
  of 
  England, 
  belongs 
  to 
  this 
  order. 
  If 
  so 
  it 
  is 
  the 
  type 
  of 
  a 
  peculiar 
  family, 
  to 
  be 
  

   known 
  by 
  the 
  absence 
  of 
  neural 
  spine 
  and 
  low 
  position 
  of 
  the 
  zygapophyses, 
  which 
  have 
  

   horizontal 
  articular 
  faces. 
  The 
  S. 
  dissimilis, 
  Seeley, 
  is 
  a 
  much 
  smaller 
  animal 
  than 
  any 
  

   here 
  enumerated, 
  and 
  is 
  known 
  by 
  a 
  single 
  vertebra.* 
  

  

  Goldfnss 
  states 
  that 
  Mosasaurus 
  possesses 
  a 
  malar 
  arch. 
  This 
  is 
  absent 
  in 
  Clidastes, 
  

   and 
  I 
  am 
  inclined 
  to 
  doubt 
  whether 
  Goldfuss 
  has 
  demonstrated 
  his 
  point 
  ; 
  if 
  present, 
  it 
  

   must 
  be 
  as 
  he 
  states, 
  very 
  slender. 
  

  

  * 
  See 
  Ann. 
  Magaz. 
  Nat, 
  Hist., 
  18(55, 
  Sept. 
  

  

  