﻿In. 
  

  

  Lin. 
  

  

  6 
  

  

  8. 
  

  

  1 
  

  

  8.5 
  

  

  1 
  

  

  i 
  . 
  

  

  

  8.5 
  

  

  

  17.5 
  

  

  72 
  THE 
  EXTINCT 
  BATRACHIA, 
  REPTILIA 
  

  

  Length, 
  

  

  " 
  to 
  middle 
  of 
  deltoid 
  crest, 
  

   Width 
  of 
  head, 
  

  

  " 
  shank 
  at 
  middle, 
  

  

  ' 
  ' 
  condyles, 
  

  

  A 
  mass 
  of 
  induarted 
  marl, 
  with 
  vivianite 
  and 
  oxide 
  of 
  iron 
  from 
  Monmouth 
  County, 
  N. 
  J., 
  submitted 
  to 
  me 
  by 
  

   Prof. 
  G. 
  H. 
  Cook, 
  contains 
  the 
  posterior 
  part 
  of 
  the 
  cranium 
  of 
  this 
  species, 
  with 
  cervical, 
  dorsal, 
  lumbar 
  and 
  caudal 
  

   vertebrae, 
  dermal 
  plates 
  and 
  coracoids. 
  The 
  individual 
  was 
  immature, 
  as 
  shown 
  by 
  the 
  non-anchylosis 
  of 
  the 
  centrum 
  

   of 
  the 
  atlas, 
  the 
  neural 
  arches, 
  etc. 
  

  

  The 
  cervical 
  has 
  the 
  small 
  hypapophysis 
  composed 
  of 
  two 
  small 
  separated 
  tubercles 
  slightly 
  prominent. 
  The 
  

   dorsal, 
  with 
  a 
  prominent 
  hypapophysis 
  which 
  is 
  trincate 
  in 
  front 
  and 
  at 
  the 
  end, 
  has 
  the 
  round 
  cup 
  characteristic 
  of 
  

   this 
  species 
  and 
  the 
  H. 
  tenebrosus. 
  The 
  dermal 
  plates 
  are 
  large, 
  elongate-quadrate, 
  considerably 
  exceeding 
  the 
  

   frontal 
  region 
  in 
  width. 
  Their 
  fossae 
  are 
  in 
  some 
  deep, 
  wider 
  than 
  the 
  interspaces, 
  in 
  others 
  smaller, 
  the 
  plate 
  with 
  

   a 
  broad 
  smooth 
  bevelled 
  border. 
  

  

  The 
  cranium 
  exhibits 
  the 
  specific 
  and 
  generic 
  characters 
  very 
  well. 
  The 
  muzzle 
  is 
  broken 
  off 
  at 
  the 
  anterior 
  

   extremity 
  of 
  the 
  pre-frontal 
  bone, 
  showing 
  that 
  there 
  is 
  no 
  foramen 
  as 
  in 
  Thoracosaurus. 
  The 
  acute 
  posterior 
  

   extremities 
  of 
  the 
  nasals 
  remain. 
  At 
  the 
  anterior 
  border 
  of 
  the 
  orbits 
  the 
  lachrymal 
  is 
  wider 
  than 
  the 
  pre-frontal, 
  

   and 
  the 
  pre-frontal 
  wider 
  than 
  the 
  frontal. 
  

  

  The 
  pre-frontal 
  suture 
  does 
  not 
  extend 
  further 
  back 
  than 
  opposite 
  the 
  middle 
  point 
  of 
  the 
  diameter 
  of 
  the 
  orbit, 
  

   No 
  part 
  of 
  the 
  orbital 
  margins 
  are 
  everted, 
  except 
  for 
  a 
  shorter 
  distance 
  on 
  the 
  malar 
  bone. 
  The 
  temporal 
  or 
  crota- 
  

   phite 
  fossae 
  are 
  of 
  about 
  the 
  same 
  area 
  as 
  the 
  orbits. 
  The 
  width 
  separating 
  them 
  is 
  very 
  little 
  less 
  than 
  one-half 
  the 
  

   distance 
  between 
  the 
  orbits. 
  The 
  anterior 
  wall 
  of 
  the 
  foramen 
  is 
  not 
  quite 
  vertical 
  as 
  in 
  H. 
  tenebrosus, 
  nor 
  very 
  

   oblique 
  as 
  in 
  another 
  species. 
  The 
  sculpture 
  is 
  less 
  marked 
  than 
  in 
  the 
  latter, 
  and 
  though 
  it 
  would 
  become 
  perhaps 
  

   more 
  profound 
  with 
  age, 
  it 
  is 
  quite 
  different 
  in 
  pattern 
  from 
  these. 
  There 
  are 
  small 
  pits 
  near 
  the 
  orbital 
  margins, 
  

   and 
  shallow 
  grooves 
  which 
  incline 
  backwards 
  towards 
  the 
  median 
  line, 
  which 
  is 
  almost 
  smooth. 
  There 
  are 
  no 
  grooves 
  

   or 
  pits 
  on 
  the 
  interparietal 
  region. 
  In 
  H. 
  obscurus 
  there 
  are 
  large 
  deep 
  jjits 
  all 
  over 
  the 
  frontal, 
  which 
  is 
  concave, 
  

   and 
  broad 
  smooth 
  margins 
  and 
  a 
  median 
  line 
  of 
  pits 
  on 
  the 
  parietal 
  bone. 
  In 
  the 
  the 
  third 
  species 
  (figured 
  by 
  Leidy 
  

   Cret. 
  Rept., 
  II., 
  8,) 
  the 
  pits 
  are 
  more 
  numerous 
  and 
  the 
  interparietal 
  wider, 
  and 
  with 
  marginal 
  grooves. 
  The 
  ante- 
  

   rior 
  face 
  of 
  the 
  crotaphite 
  fossa 
  is 
  very 
  oblique, 
  or 
  thickened 
  inwards 
  below, 
  while 
  it 
  is 
  vertical 
  in 
  the 
  H. 
  

   obscurus. 
  

  

  Postfrontal 
  

  

  Frontal 
  

  

  Parietal 
  

  

  suture, 
  width. 
  

  

  width. 
  

  

  width. 
  

  

  .52 
  

  

  1.23 
  

  

  .G 
  

  

  .8 
  

  

  2. 
  

  

  .55 
  

  

  .7 
  

  

  1.95 
  

  

  .68 
  

  

  H. 
  brevispinis, 
  

   H. 
  obscurus, 
  

   H. 
  ?sp., 
  

  

  The 
  surfaces 
  of 
  the 
  malar, 
  postfronto-parietal 
  and 
  post-temporal 
  arches 
  are 
  marked 
  with 
  distant 
  shallow 
  pits. 
  

   The 
  superior 
  concealed 
  insertion 
  surfaces 
  of 
  the 
  supraoccipital 
  are 
  largely 
  exposed, 
  and 
  rugose. 
  

  

  The 
  basioccipital, 
  sphenoid 
  and 
  pterygoids 
  are 
  more 
  or 
  less 
  exposed. 
  The 
  first 
  is 
  vertical, 
  with 
  latero-inferior 
  

   processes 
  directed 
  upwards. 
  The 
  sphenoid 
  has 
  a 
  very 
  narrow 
  exposure, 
  but 
  this 
  is 
  horizontal. 
  The 
  posterior-inner 
  

   processes 
  of 
  the 
  pterygoid 
  lie 
  closely 
  appresscd 
  to 
  the 
  sphenoid 
  and 
  basioccipital 
  laterally. 
  This 
  arrangement 
  is 
  much 
  

   as 
  in 
  the 
  living 
  Gavialis 
  gangeticus. 
  The 
  posterior 
  nares 
  are 
  more 
  anterior, 
  however, 
  and 
  the 
  septum 
  not 
  completed. 
  

   Their 
  plane 
  is 
  perhaps 
  a 
  little 
  above 
  that 
  of 
  the 
  orifice 
  of 
  the 
  eustachian 
  tubes. 
  The 
  lower 
  extremity 
  of 
  the 
  basi- 
  

   occipital, 
  has 
  a 
  well-marked 
  posterior 
  keel. 
  

  

  