﻿0. 
  C. 
  Marsh 
  — 
  Notice 
  of 
  New 
  Vertebrate 
  Fossils. 
  269 
  

  

  The 
  length 
  of 
  this 
  skull 
  on 
  the 
  median 
  line 
  is 
  about 
  thirty 
  

   inches, 
  and 
  the 
  width 
  across 
  the 
  zygomatic 
  arches 
  twenty-three 
  

   inches. 
  The 
  width 
  across 
  the 
  horn-cores 
  is 
  fourteen 
  inches. 
  

   The 
  extent 
  of 
  the 
  superior 
  dental 
  series 
  is 
  sixteen 
  inches. 
  

  

  The 
  type 
  of 
  this 
  species 
  was 
  found 
  in 
  the 
  Brontotherium 
  

   beds 
  of 
  South 
  Dakota, 
  by 
  Mr. 
  J. 
  B. 
  Hatcher. 
  

  

  Brontops 
  validus, 
  sp. 
  no 
  v. 
  

  

  This 
  well-marked 
  species 
  is 
  based 
  upon 
  a 
  skull 
  in 
  fine 
  

   preservation, 
  which 
  agrees 
  in 
  its 
  main 
  characters 
  with 
  the 
  

   other 
  species 
  of 
  this 
  genus, 
  but 
  is 
  particularly 
  short 
  and 
  

   robust. 
  The 
  zygomatic 
  arches 
  are 
  widely 
  expanded, 
  almost 
  

   as 
  much 
  as 
  in 
  any 
  skull 
  of 
  this 
  group. 
  The 
  nasal 
  bones 
  have 
  

   only 
  a 
  moderate 
  extension 
  in 
  front, 
  and 
  do 
  not 
  reach 
  the 
  end 
  

   of 
  the 
  premaxillaries. 
  The 
  free 
  portion 
  is 
  broad 
  and 
  massive. 
  

   The 
  horn-cores 
  are 
  of 
  moderate 
  size, 
  nearly 
  round 
  in 
  section, 
  

   and 
  have 
  their 
  obtuse 
  summits 
  directed 
  somewhat 
  backward. 
  

   The 
  occipital 
  crest 
  slopes 
  forward, 
  and 
  is 
  expanded 
  transversely. 
  

   The 
  length 
  of 
  this 
  skull 
  on 
  the 
  median 
  line 
  is 
  about 
  twenty-six 
  

   inches. 
  The 
  greatest 
  transverse 
  diameter 
  across 
  the 
  zygomatic 
  

   arches 
  is 
  twenty-two 
  inches, 
  and 
  across 
  the 
  summits 
  of 
  the 
  

   horn-cores, 
  fourteen 
  inches. 
  

  

  The 
  type 
  specimen 
  of 
  the 
  present 
  species 
  is 
  from 
  the 
  

   Brontotherium 
  beds 
  of 
  South 
  Dakota, 
  where 
  it 
  was 
  secured 
  

   by 
  Mr. 
  J. 
  B. 
  Hatcher. 
  

  

  Titanops 
  medius, 
  sp. 
  no 
  v. 
  

  

  The 
  present 
  species 
  is 
  from 
  nearly 
  the 
  same 
  horizon 
  as 
  the 
  

   type 
  of 
  the 
  genus, 
  but 
  is 
  of 
  smaller 
  size. 
  It 
  is 
  represented 
  by 
  

   one 
  skull 
  in 
  fair 
  preservation, 
  with 
  the 
  horn-cores 
  and 
  dentition 
  

   complete. 
  The 
  free 
  portion 
  of 
  the 
  nasals 
  is 
  very 
  small, 
  and 
  

   projects 
  but 
  slightly 
  beyond 
  the 
  anterior 
  line 
  of 
  the 
  horn-cores. 
  

   The 
  latter 
  are 
  compressed 
  antero-posteriorly, 
  and 
  project 
  

   laterally 
  nearly 
  at 
  right 
  angles 
  to 
  the 
  median 
  line 
  of 
  the 
  skull. 
  

   The 
  two 
  incisors 
  on 
  each 
  side 
  are 
  quite 
  small, 
  and 
  separated 
  

   from 
  each 
  other 
  and 
  from 
  the 
  canine. 
  There 
  is 
  a 
  slight 
  diastema 
  

   behind 
  the 
  canine. 
  The 
  first 
  premolar 
  is 
  small, 
  and 
  triangular 
  

   in 
  outline. 
  The 
  second 
  premolar 
  is 
  of 
  moderate 
  size, 
  and 
  the 
  

   third 
  and 
  fourth 
  premolars 
  have 
  only 
  an 
  incomplete 
  inner 
  

   basal 
  ridge. 
  

  

  The 
  width 
  of 
  this 
  skull 
  across 
  the 
  horn- 
  cores 
  is 
  twenty-three 
  

   inches, 
  and 
  the 
  distance 
  from 
  the 
  end 
  of 
  the 
  nasals 
  to 
  the 
  

   front 
  of 
  the 
  posterior 
  nares 
  is 
  sixteen 
  inches. 
  The 
  extent 
  of 
  

   the 
  upper 
  dental 
  series 
  is 
  seventeen 
  inches. 
  This 
  specimen 
  is 
  

   from 
  near 
  the 
  top 
  of 
  the 
  Brontotherium 
  beds 
  of 
  South 
  Dakota, 
  

  

  k 
  where 
  it 
  was 
  discovered 
  by 
  Mr. 
  J. 
  B. 
  Hatcher. 
  

   New 
  Haven, 
  Conn., 
  August 
  10th, 
  1891. 
  

  

  