﻿VEETEBEATES. 
  101 
  

  

  The 
  above 
  diagnosis 
  applies 
  to 
  a 
  certain 
  form 
  of 
  teeth 
  well 
  rep- 
  

   resented 
  in 
  the 
  collections 
  from 
  various 
  Lower 
  Carboniferous 
  

   formations, 
  and 
  which 
  is 
  homologous 
  with 
  the 
  long 
  posterior 
  teeth 
  

   of 
  the 
  upper 
  jaw, 
  formerly 
  embraced 
  under 
  the 
  generic 
  term 
  Strehlodus 
  

   Agass. 
  Since 
  it 
  is 
  now 
  a 
  well 
  established 
  fact 
  that 
  the 
  latter 
  form 
  

   formed 
  part 
  of 
  the 
  dental 
  armament 
  of 
  the 
  jaws 
  of 
  the 
  same 
  fish 
  

   that 
  bore 
  the 
  teeth 
  represented 
  by 
  the 
  original 
  form 
  of 
  Cochliodus, 
  

   Agass., 
  there 
  can 
  scarcely 
  arise 
  a 
  question 
  as 
  to 
  the 
  position 
  the 
  

   present 
  form 
  held 
  upon 
  the 
  jaw. 
  

  

  It 
  may, 
  perhaps, 
  be 
  deemed 
  premature 
  at 
  the 
  present 
  time 
  to 
  

   attempt 
  the 
  identification 
  with 
  the 
  above 
  form 
  of 
  other 
  and 
  asso- 
  

   ciate 
  teeth 
  from 
  amongst 
  the 
  detached 
  dental 
  remains 
  of 
  Cochlio- 
  

   donts, 
  alone 
  contained 
  in 
  the 
  collections; 
  but 
  there 
  are 
  certain 
  

   forms 
  whose 
  occurrence 
  and 
  intimate 
  association 
  in 
  the 
  same 
  de- 
  

   posits 
  with 
  that 
  above 
  noticed, 
  strongly 
  suggest 
  their 
  congeneric 
  

   relations 
  and 
  specific 
  indentity. 
  Thus, 
  there 
  are 
  found 
  teeth 
  which, 
  

   possessing 
  the 
  general 
  characteristics 
  attributed 
  to 
  the 
  large 
  posterior 
  

   teeth 
  of 
  the 
  mandible 
  of 
  Cochliodus, 
  may 
  be 
  especially 
  characterized 
  

   by 
  their 
  more 
  trapezoidal 
  outline, 
  posterior 
  position 
  of 
  the 
  median 
  

   lobe, 
  narrow 
  posterior 
  alation, 
  and 
  the 
  relatively 
  broad 
  flat 
  area 
  of 
  

   the 
  neck 
  or 
  anterior 
  portion 
  of 
  the 
  coronal 
  region. 
  The 
  latter 
  form 
  

   is 
  further 
  distinguished 
  by 
  the 
  greater 
  or 
  less 
  obliquity 
  of 
  the 
  out- 
  

   ward 
  and 
  backward 
  course 
  of 
  the 
  antero-lateral 
  border, 
  which, 
  

   together 
  with 
  the 
  postero-lateral 
  border, 
  presents 
  the 
  same 
  condition 
  

   of 
  narrow, 
  rounded, 
  inbeveled 
  enamel 
  fold 
  and 
  channeled 
  basal 
  rim 
  

   observed 
  in 
  connection 
  with 
  the 
  opposite 
  maxillary 
  teeth, 
  with 
  which 
  

   they 
  also 
  agree 
  in 
  the 
  degree 
  of 
  inrollment 
  and 
  longitudinal 
  convex- 
  

   ity 
  of 
  the 
  coronal 
  region. 
  The 
  neck 
  or 
  anterior 
  area 
  is 
  nearly 
  plane 
  

   or 
  faintly 
  swollen 
  transversely, 
  sometimes 
  with 
  a 
  slight 
  depression 
  

   near 
  to 
  and 
  parallel 
  with 
  the 
  antero-lateral 
  border. 
  The 
  posterior 
  

   alation 
  is 
  narrow 
  and 
  separated 
  from. 
  the 
  median 
  lobe 
  by 
  a 
  compar- 
  

   atively 
  narrow 
  depression. 
  The 
  inner 
  margin 
  is 
  moderately 
  concave 
  

   in 
  passing 
  the 
  posterior 
  depression, 
  broadly 
  arched 
  round 
  the 
  base 
  

   of 
  the 
  coronal 
  prominence, 
  and 
  thence 
  to 
  the 
  anterior 
  angle 
  more 
  

   gently 
  curved 
  or 
  nearly 
  straight. 
  The 
  relative 
  proportions 
  of 
  the 
  

   teeth 
  are 
  laterally 
  narrower 
  and 
  stouter 
  than 
  the 
  maxillary 
  posterior 
  

   form. 
  

  

  There 
  are 
  associated 
  with 
  the 
  two 
  most 
  numerously 
  represented 
  

   species 
  of 
  the 
  genus 
  a 
  form 
  of 
  teeth, 
  which 
  from 
  their 
  general 
  

   appearance 
  and 
  apparent 
  identity 
  of 
  coronal 
  structure, 
  we 
  have 
  pre- 
  

  

  