﻿COOKK 
  : 
  THE 
  KADULA 
  IN 
  THAIS, 
  ETC. 
  107 
  

  

  denticle 
  close 
  to 
  them 
  ou 
  the 
  inside 
  ; 
  external 
  part 
  of 
  upper 
  margin 
  

   curiously 
  raised, 
  almost 
  toothed. 
  

  

  triangulata, 
  Pease 
  : 
  Samoa. 
  Central 
  and 
  side 
  cusps 
  rather 
  short 
  ; 
  

   the 
  interior 
  denticle 
  blunt, 
  well 
  away 
  from 
  the 
  side 
  cusp. 
  

  

  tuberculata, 
  Blaiiiv. 
  : 
  Mauritius. 
  Central 
  cusp 
  remarkably 
  short, 
  

   blunt, 
  almost 
  equal 
  in 
  length 
  to 
  side 
  cusp; 
  side 
  cusps 
  stumpy, 
  with 
  

   a 
  large 
  blunt 
  denticle 
  close 
  to 
  their 
  inner 
  base 
  ; 
  upper 
  angles 
  of 
  the 
  

   margin 
  raised 
  and 
  terminating 
  in 
  what 
  is 
  almost 
  a 
  knob. 
  

  

  undata, 
  Chem. 
  : 
  Karachi. 
  Central 
  cusp 
  rather 
  narrow; 
  side 
  

   cusps 
  large 
  and 
  broad 
  ; 
  interior 
  denticle 
  long, 
  prominent, 
  close 
  to 
  the 
  

   side 
  cusp. 
  

  

  Another 
  specimen 
  from 
  Isipingo 
  shows 
  the 
  side 
  cusps 
  inclining 
  

   somewhat 
  inward. 
  

  

  Ceonia, 
  H. 
  & 
  a. 
  Adams. 
  

  

  C. 
  amygdalus, 
  Kien. 
  : 
  Torres 
  Str., 
  Port 
  Jackson. 
  General 
  plan 
  

   of 
  the 
  radula 
  markedly 
  that 
  of 
  Ilorula; 
  central 
  cusp 
  long, 
  

   thick, 
  and 
  narrow, 
  but 
  not 
  deeply 
  sunk 
  in 
  a 
  pit, 
  root 
  carried 
  through 
  

   to 
  the 
  base 
  and 
  projecting 
  ; 
  side 
  cusps 
  rather 
  smaller, 
  with 
  a 
  small 
  

   sharp 
  tooth 
  on 
  the 
  inside, 
  close 
  to 
  but 
  separate 
  from 
  the 
  cusp 
  ; 
  no 
  

   denticles 
  outside, 
  no 
  knob 
  ; 
  base 
  boldly 
  waved 
  by 
  the 
  projection 
  of 
  

   the 
  root 
  of 
  the 
  median 
  cusp. 
  The 
  little 
  isolated 
  denticle 
  is 
  not 
  so 
  

   low 
  down 
  as 
  in 
  Iforula, 
  being 
  nearly, 
  though 
  not 
  quite 
  in 
  the 
  same 
  

   plane 
  as 
  the 
  side 
  cusps; 
  base 
  of 
  laterals 
  much 
  prolonged. 
  (Fig. 
  33.) 
  

  

  Cronia 
  therefore 
  forms 
  another 
  link 
  between 
  Thais 
  pi-oper 
  and 
  

   Morula, 
  but 
  its 
  relationship 
  to 
  Morula 
  is 
  much 
  closer 
  than 
  is 
  that 
  of 
  

   Cymia. 
  Cymia 
  may 
  be 
  regarded 
  as 
  a 
  modified 
  Thais, 
  Cronia 
  is 
  

   a 
  scarcely 
  modified 
  Aforula. 
  

  

  Mr. 
  Hedley, 
  I 
  am 
  told 
  by 
  Mr. 
  Iredale, 
  names 
  Cronia 
  from 
  these 
  

   localities 
  pseudamygdalus, 
  restricting 
  amygdalus 
  to 
  Sydney 
  and 
  the 
  

   east 
  coast. 
  

  

  Ctmia, 
  Mcirch. 
  

  

  The 
  single 
  species 
  {tectum, 
  Wood, 
  see 
  A. 
  H. 
  Cooke 
  in 
  Journ. 
  of 
  

   Conch., 
  V, 
  pp. 
  167-72, 
  1887) 
  of 
  this 
  genus 
  exhibits 
  a 
  central 
  cusp 
  which 
  

   is 
  long, 
  thick, 
  rather 
  narrow, 
  deeply 
  set 
  in 
  a 
  pit 
  and 
  cut 
  in; 
  side 
  cusps 
  

   decidedly 
  shorter, 
  broadly 
  triangular, 
  very 
  strongly 
  singly 
  denticled 
  

   low 
  down 
  on 
  the 
  inside, 
  the 
  inner 
  edge 
  of 
  the 
  denticle 
  descending 
  

   low 
  and 
  rooted 
  deep, 
  as 
  in 
  Morula. 
  On 
  the 
  outside 
  edge 
  of 
  the 
  side 
  

   cusp, 
  low 
  down, 
  is 
  an 
  obscure 
  blunt 
  denticle 
  or 
  corrugation 
  ; 
  this 
  

   denticle 
  is 
  not 
  a 
  separate 
  toothlet 
  like 
  the 
  exterior 
  denticles 
  in 
  

   Thais, 
  but 
  forms 
  part 
  of 
  the 
  cusp 
  itself 
  ; 
  outside 
  this 
  again, 
  as 
  a 
  rule, 
  

   there 
  is 
  nothing 
  but 
  the 
  knob, 
  but 
  in 
  some 
  specimens 
  there 
  is 
  

   another 
  tiny 
  blunt 
  denticle 
  close 
  to 
  the 
  knob 
  ; 
  knob 
  prominent 
  ; 
  

   base 
  deeply 
  waved, 
  with 
  root 
  of 
  central 
  cusp 
  projecting 
  through. 
  

   (Fig. 
  31.) 
  

  

  Cymia 
  thus 
  forms 
  a 
  good 
  link 
  between 
  Thais 
  and 
  Morula 
  : 
  the 
  

   attached 
  denticle 
  on 
  the 
  inner 
  side 
  of 
  the 
  side 
  cusps, 
  the 
  symptom 
  of 
  

   an 
  external 
  denticle, 
  and 
  the 
  prominent 
  knob 
  showing 
  affinity 
  with 
  

   Thais, 
  On 
  the 
  other 
  hand, 
  the 
  narrow 
  thick 
  central 
  cusp, 
  the 
  pit 
  

   in 
  which 
  it 
  is 
  placed, 
  and 
  above 
  all 
  the 
  carrying 
  of 
  the 
  root 
  right 
  

  

  