﻿n. 
  

  

  Lin. 
  

  

  3 
  

  

  3.3 
  

  

  2 
  

  

  3. 
  

  

  2 
  

  

  4.8 
  

  

  4 
  

  

  8 
  

  

  

  8.5 
  

  

  2 
  

  

  11.6 
  

  

  

  11 
  

  

  

  19.2 
  

  

  

  11. 
  

  

  AND 
  AVES 
  OF 
  NORTH 
  AMERICA. 
  195 
  

  

  This 
  ridge' 
  is 
  the 
  external 
  distal 
  longitudinal 
  of 
  the 
  other 
  species, 
  very 
  much 
  developed. 
  In 
  M. 
  oarthrus 
  it 
  is 
  separated 
  

   by 
  considerable 
  interval 
  from 
  the 
  median 
  posterior; 
  in 
  M. 
  dekayi 
  it 
  just 
  attains 
  it; 
  here, 
  it 
  extends 
  along 
  the 
  side 
  of 
  

   and 
  in 
  front 
  of 
  it, 
  to 
  the 
  rugose 
  area 
  in 
  front 
  of 
  the 
  pit. 
  Its 
  prominence 
  produces 
  a 
  produced 
  external 
  posterior 
  angle 
  

   on 
  the 
  distal 
  articular 
  extremity. 
  The 
  median 
  posterior 
  is 
  much 
  prolonged 
  downwards, 
  and 
  is 
  very 
  rugose; 
  a 
  ridge 
  is 
  

   also 
  continued 
  from 
  the 
  knob 
  to 
  near 
  the 
  distal 
  articular 
  extremity, 
  and 
  its 
  line 
  is 
  the 
  point 
  of 
  convergence 
  for 
  two 
  

   series 
  of 
  strong 
  rugae. 
  The 
  anterior 
  inner 
  ridge 
  is 
  strongly 
  pronounced. 
  

  

  The 
  general 
  size 
  of 
  this 
  species 
  is 
  not 
  more 
  than 
  half 
  that 
  of 
  M. 
  dekayi. 
  

  

  The 
  supposed 
  humerus 
  has 
  a 
  flattened 
  shaft, 
  becoming 
  more 
  cylindric 
  proxiinally. 
  It 
  looks 
  as 
  though 
  it 
  had 
  

   been 
  used 
  by 
  Indians 
  as 
  a 
  pestle. 
  

  

  Length 
  posterior 
  dorsal, 
  

  

  Depth 
  cup 
  " 
  " 
  

  

  Width 
  " 
  " 
  " 
  

  

  Length 
  of 
  os 
  quadratum, 
  

  

  Width 
  of 
  dorsal 
  rib, 
  

  

  From 
  knob 
  to 
  external 
  angular 
  quadrate, 
  

  

  Diameter 
  proximal 
  extremity, 
  (average) 
  

  

  ' 
  ' 
  transverse, 
  of 
  body 
  at 
  knob, 
  

  

  " 
  " 
  distal 
  extremity, 
  

  

  MOSASAURUS 
  MISSURIENSIS, 
  Harlan. 
  

  

  Ichthyosaurus 
  do., 
  Harlan, 
  Trans. 
  Amer. 
  Philos. 
  Soc, 
  IV, 
  405, 
  Tab. 
  X*X, 
  1834. 
  Batrachiosaurus, 
  Harlan. 
  Ba- 
  

   trachiotherium, 
  Harlan. 
  ? 
  Mosasaurus 
  neovidii, 
  Meyer. 
  ?if. 
  maxirniliani, 
  Goldfuss. 
  M. 
  missuriensis, 
  Leidy, 
  Cretac. 
  

   Rept. 
  VII, 
  p. 
  15, 
  16, 
  17, 
  18. 
  

  

  The 
  centra 
  of 
  the 
  vertebrae 
  of 
  this 
  species 
  are 
  moderately 
  depressed. 
  The 
  centra 
  of 
  the 
  caudals, 
  posterior 
  to 
  the 
  

   disappearance 
  of 
  the 
  diapophyses, 
  are 
  as 
  wide 
  as 
  deep, 
  and 
  of 
  nearly 
  similar 
  length, 
  and 
  with 
  anchylosed 
  chevron 
  

   bones. 
  A 
  fine 
  cranium 
  is 
  figured 
  by 
  Goldfuss, 
  and 
  he 
  shows 
  the 
  crowns 
  of 
  the 
  teeth 
  to 
  be 
  subcylindric, 
  incurved 
  and 
  

   facetted. 
  

  

  An 
  unusually 
  perfect 
  specimen 
  of 
  this 
  species, 
  or 
  one 
  allied 
  to 
  it, 
  was 
  recently 
  exhumed 
  by 
  W. 
  E. 
  Webb, 
  near 
  

  

  the 
  town 
  of 
  Topeka 
  in 
  Kansas. 
  My 
  friend, 
  Prof. 
  J. 
  Parker, 
  of 
  Lincoln 
  College, 
  of 
  that 
  place, 
  informs 
  me 
  that 
  it 
  is 
  

  

  seventy-five 
  feet 
  in 
  length, 
  and 
  the 
  gentleman 
  who 
  discovered 
  it, 
  that 
  it 
  measures 
  eighty 
  feet. 
  Its 
  mandibular 
  rami 
  

  

  are 
  stated 
  by 
  the 
  same 
  person 
  to 
  measure 
  five 
  feet. 
  Measurements 
  of 
  the 
  vertebrae 
  iudicate 
  them 
  to 
  be 
  of 
  a 
  size 
  quite 
  

  

  similar 
  to 
  those 
  of 
  large 
  individuals 
  which 
  have 
  been 
  discovered 
  in 
  the 
  green 
  sand 
  of 
  New 
  Jersey. 
  They 
  measure 
  as 
  

  

  follows, 
  as 
  stated 
  on 
  photographs 
  by 
  my 
  friend, 
  "W. 
  E. 
  Webb. 
  

  

  Inches. 
  

  

  Diameter 
  cervicals 
  centra 
  only, 
  2.5 
  

  

  " 
  dorsals, 
  with 
  diapophyses, 
  7 
  

  

  ' 
  ' 
  lumbars, 
  2 
  

  

  These 
  proportions 
  illustrate 
  again 
  the 
  Ophidian 
  or 
  eel-like 
  form 
  of 
  this 
  genus, 
  and 
  the 
  relatively 
  large 
  size 
  of 
  the 
  

  

  head. 
  

  

  The 
  teeth 
  resemble 
  in 
  size 
  those 
  of 
  large 
  specimens 
  of 
  M. 
  dekayi. 
  

  

  The 
  following 
  corrections 
  should 
  be 
  made 
  in 
  the 
  nomenclature 
  adopted 
  by 
  Goldfuss 
  in 
  the 
  explanations 
  of 
  his 
  

  

  plate, 
  Nova 
  Acta. 
  Nat. 
  Cur., 
  1855, 
  Tab. 
  VI 
  to 
  XL 
  

  

  Tab. 
  VI. 
  

   T- 
  is 
  Squamosal, 
  called 
  temporal. 
  

  

  T. 
  m. 
  is 
  Opisthotic, 
  " 
  temporo-mastoid. 
  

  

  T. 
  p. 
  is 
  ProiJtic 
  and 
  Epiotic. 
  

  

  P. 
  is 
  a 
  thin 
  lamina 
  of 
  parietal 
  prolonged 
  backwards 
  over 
  supraoccipital. 
  

  

  Tab. 
  XL 
  

  

  2 
  ? 
  ? 
  said 
  to 
  be 
  pubis. 
  

  

  3 
  is 
  Quadratum, 
  " 
  " 
  Olecranon. 
  

  

  From 
  the 
  upper 
  cretaceous 
  of 
  middle 
  North 
  America. 
  

  

  