﻿VEETEBEATES. 
  215 
  

  

  tudinal 
  depression 
  is 
  discernible 
  a 
  little 
  within 
  and 
  parallel 
  with 
  the 
  

   outer 
  border. 
  The 
  surface 
  is 
  smooth 
  and 
  full, 
  the 
  superficial 
  struc- 
  

   tural 
  details 
  exactly 
  agreeing 
  with 
  those 
  observed 
  in 
  the 
  preceding 
  

   form. 
  In 
  the 
  unworn 
  rounded 
  outer 
  border 
  of 
  one 
  or 
  two 
  specimens 
  

   the 
  coronal 
  enamel 
  presents 
  faint 
  rugosities 
  apparently 
  conforming 
  

   to 
  the 
  lines 
  of 
  growth, 
  and 
  which 
  must 
  have 
  produced 
  an 
  exceed- 
  

   ingly 
  delicate 
  sculptured 
  appearance 
  in 
  the 
  surface. 
  A 
  small 
  indi- 
  

   vidual 
  measures 
  in 
  transverse 
  diameter 
  across 
  the 
  posterior 
  margin 
  

   13 
  millimetres 
  ; 
  length 
  along 
  the 
  inner 
  border 
  14 
  mm. 
  A 
  medium- 
  

   size 
  specimen 
  is 
  35 
  mm., 
  and 
  26 
  mm. 
  in 
  the 
  same 
  dimensions; 
  and 
  

  

  the 
  largest 
  individual 
  as 
  yet 
  observed 
  shows 
  a 
  lateral 
  breadth 
  of 
  53 
  

   mm. 
  

  

  The 
  above 
  described 
  forms 
  undoubtedly 
  pertained 
  to 
  one 
  and 
  the 
  

   same 
  species. 
  They 
  occur 
  in 
  the 
  collections 
  in 
  about 
  equal 
  numbers, 
  

   and 
  present 
  precisely 
  the 
  same 
  superficial 
  features 
  in 
  all 
  respects 
  

   save 
  outline 
  and 
  contour. 
  The 
  supposed 
  maxillary 
  teeth 
  apparently 
  

   vary 
  but 
  little 
  in 
  proportions. 
  The 
  larger 
  teeth 
  differing 
  from 
  the 
  

   small 
  ones 
  chiefly 
  in 
  the 
  greater 
  basal 
  development 
  in 
  the 
  region 
  of 
  

   the 
  outer 
  border. 
  A 
  fragment 
  of 
  a 
  very 
  large 
  tooth 
  obtained 
  by 
  Mr. 
  

   Alexander 
  Butters, 
  representing 
  an 
  individual 
  which 
  was 
  probably 
  

   not 
  less 
  than 
  90 
  millimeters 
  in 
  lateral 
  diameter, 
  presents 
  the 
  same 
  

   coronal 
  contour 
  in 
  every 
  particular, 
  save 
  the 
  rounded 
  posterior 
  angle 
  

   of 
  the 
  inner 
  border 
  and 
  the 
  irregular, 
  deeply 
  scolloped 
  posterior 
  

   margin, 
  which 
  may 
  be 
  likened 
  to 
  a 
  line 
  of 
  overhanging 
  cliffs. 
  The 
  

   latter 
  specimen 
  is 
  also 
  of 
  interest 
  on 
  account 
  of 
  showing 
  the 
  perma- 
  

   nence 
  of 
  depth 
  maintained 
  by 
  the 
  enamel 
  belt, 
  which 
  is 
  dispropor- 
  

   tionately 
  shallow 
  as 
  compared 
  with 
  the 
  relative 
  dimensions 
  of 
  the 
  

   tooth, 
  while 
  the 
  basal 
  portion 
  is 
  excessively 
  developed. 
  

  

  In 
  regard 
  to 
  the 
  supposed 
  mandibular 
  teeth, 
  there 
  is 
  observable 
  

   a 
  much 
  greater 
  latitude 
  in 
  variability, 
  especially 
  in 
  the 
  proportions, 
  

   with 
  age. 
  The 
  earlier 
  formed 
  teeth 
  are 
  relatively 
  longer, 
  while 
  the 
  

   larger 
  individuals 
  show 
  a 
  greater 
  transverse 
  breadth, 
  with 
  which 
  

   latter 
  character 
  is 
  also 
  associated 
  that 
  noted 
  in 
  large 
  examples 
  of 
  

   the 
  opposed 
  form, 
  in 
  which 
  the 
  basal 
  portion 
  is 
  developed 
  into 
  a 
  

   prominent 
  flange 
  along 
  the 
  exterior 
  border. 
  The 
  collections 
  contain 
  

   two 
  large 
  teeth, 
  which 
  differ 
  so 
  greatly 
  from 
  the 
  normal 
  condition 
  

   of 
  medium 
  and 
  small-sized 
  examples, 
  that 
  they 
  might 
  be 
  mistaken 
  

   for 
  representatives 
  of 
  a 
  distinct 
  species. 
  The 
  latter 
  teeth 
  are 
  very 
  

   broad 
  compared 
  to 
  the 
  length, 
  and 
  to 
  further 
  obscure 
  their 
  proba- 
  

   ble 
  actual 
  specific 
  identity, 
  the 
  posterior 
  margin 
  is 
  in 
  both 
  cases 
  

   broken 
  away, 
  its 
  outline 
  conforming 
  to 
  the 
  backward-arched 
  lines 
  of 
  

  

  