﻿96 
  PROCEEDINGS 
  OF 
  THE 
  MALACOLOGICAL 
  SOCIETY. 
  

  

  Troscliel's 
  figure 
  is 
  legendary. 
  

  

  luteostoma, 
  Cham.: 
  China. 
  Central 
  cusp 
  strong, 
  broad, 
  and 
  long; 
  

   side 
  cusps 
  about 
  lialf 
  as 
  long, 
  sharply 
  pointed, 
  on 
  the 
  inside 
  is 
  a 
  

   denticle, 
  prominent, 
  sharp 
  or 
  blunt, 
  set 
  at 
  varying 
  heights, 
  but 
  

   usually 
  low 
  down, 
  sometimes 
  nearly 
  half-way 
  up, 
  and 
  occasionally 
  

   itself 
  doubled 
  or 
  denticled 
  ; 
  outside, 
  one 
  or 
  two 
  small 
  climbing 
  

   denticles, 
  then 
  4-5, 
  prominent; 
  knob 
  blunt. 
  

  

  In 
  one 
  specimen 
  there 
  are 
  7-8 
  exterior 
  denticles, 
  four 
  of 
  which 
  

   climb, 
  the 
  upper 
  ones 
  rising 
  near 
  to 
  the 
  apex 
  of 
  the 
  cusp. 
  

  

  melo?ies, 
  Duel. 
  : 
  Panama. 
  Central 
  cusp 
  about 
  one-tliird 
  longer 
  than 
  

   the 
  side 
  cusps, 
  moderately 
  broad, 
  side 
  cusps 
  broad, 
  with 
  a 
  very 
  strong 
  

   denticle 
  low 
  down, 
  deeply 
  cut, 
  and 
  almost 
  free 
  of 
  the 
  cusps, 
  

   inclining 
  towards 
  them, 
  and 
  occasionally 
  irregular 
  in 
  shape; 
  outside, 
  

   1-2 
  very 
  faint 
  blunt 
  denticles, 
  not 
  climbing; 
  knob 
  blunt, 
  prominent. 
  

   (Fig. 
  6.) 
  

  

  nentoides, 
  L. 
  : 
  St. 
  Vincent, 
  Cape 
  Verd. 
  Central 
  cusp 
  broad 
  

   and 
  thick, 
  nearly 
  twice 
  as 
  long 
  as 
  the 
  side 
  cusps, 
  side 
  cusps 
  not 
  

   denticled 
  inside; 
  outside, 
  no 
  denticles, 
  but 
  occasionally 
  a 
  small 
  very 
  

   blunt 
  hump 
  at 
  the 
  base 
  of 
  the 
  cusps 
  ; 
  knob 
  blunt, 
  not 
  prominent. 
  

  

  A 
  specimen 
  of 
  the 
  var. 
  asce)istonis 
  (Ascension 
  I.) 
  is 
  strongly 
  denticled 
  

   about 
  half-way 
  up 
  the 
  inside 
  of 
  the 
  side 
  cusps, 
  with 
  two 
  well- 
  

   marked 
  denticles 
  outside 
  and 
  traces 
  of 
  a 
  third, 
  smaller, 
  climbing. 
  

  

  Compare 
  coronata 
  for 
  this 
  divergence, 
  as 
  regards 
  denticles, 
  

   between 
  the 
  typical 
  form 
  and 
  varieties. 
  

  

  persica, 
  L. 
  : 
  Colombo. 
  Central 
  cusp 
  long 
  and 
  broad, 
  side 
  cusps 
  

   long, 
  broadening 
  considerably 
  at 
  and 
  below 
  the 
  denticle, 
  denticle 
  

   small 
  but 
  conspicuous, 
  two-thirds 
  way 
  down; 
  outside, 
  4-5 
  strong 
  

   deeply 
  cut 
  denticles, 
  one 
  of 
  which 
  climbs 
  ; 
  knob 
  large 
  and 
  elevated. 
  

   (Fig. 
  15.) 
  

  

  petiti, 
  Melv. 
  : 
  Charbar. 
  Central 
  cusp 
  long 
  and 
  thick, 
  side 
  cusps 
  

   short, 
  rather 
  stumpy, 
  with 
  a 
  strong 
  short 
  denticle 
  on 
  the 
  inside; 
  

   outside, 
  three 
  rather 
  blunt 
  denticles, 
  one 
  of 
  which 
  is 
  climbing; 
  knob 
  

   prominent. 
  

  

  pica, 
  Blainv. 
  : 
  Java. 
  Central 
  cusp 
  long, 
  massive, 
  two-thirds 
  longer 
  

   than 
  the 
  side 
  cusps, 
  which 
  are 
  decidedly 
  narrower, 
  one 
  small 
  denticle 
  

   between 
  the 
  central 
  and 
  side 
  cusps, 
  but 
  not 
  attached 
  to 
  either 
  ; 
  

   outside, 
  no 
  denticles, 
  but 
  faint 
  symptoms 
  of 
  a 
  few 
  wrinkles; 
  knob 
  

   rather 
  blunt. 
  (Fig. 
  2.) 
  

  

  rudolphi, 
  Lam. 
  : 
  Natal. 
  Central 
  cusp 
  long 
  and 
  pointed, 
  often 
  

   furnished 
  with 
  a 
  guard, 
  broadening 
  at 
  its 
  base, 
  side 
  cusps 
  broadly 
  

   triangular 
  and 
  pointed, 
  rather 
  shorter 
  than 
  in 
  persica, 
  a 
  sharp 
  

   denticle 
  low 
  down 
  on 
  the 
  inside; 
  outside, 
  3-4 
  strong 
  conspicuous 
  

   denticles, 
  not 
  climbing; 
  knob 
  prominent 
  and 
  high. 
  

  

  Three 
  different 
  specimens 
  have 
  four 
  denticles 
  on 
  one 
  side 
  of 
  the 
  

   cusps 
  and 
  three 
  on 
  the 
  other; 
  sometimes 
  the 
  knob 
  is 
  bifid. 
  

  

  saceUum, 
  Chem. 
  : 
  Charbar. 
  Central 
  cusp 
  sharp, 
  rather 
  long, 
  

   broadening 
  rapidly 
  near 
  its 
  base, 
  side 
  cusps 
  blunt 
  and 
  broad, 
  with 
  

   a 
  rather 
  obscure 
  denticle 
  about 
  half-wny 
  up 
  ; 
  outside, 
  3-4 
  small 
  

   denticles, 
  one 
  or 
  two 
  of 
  which 
  climb; 
  knob 
  blunt; 
  base 
  waved 
  in 
  

   the 
  centre. 
  

  

  