﻿52 
  Descriptio7is 
  of 
  New 
  Species 
  and 
  Varieties 
  of 
  Shells, 
  

  

  mens 
  I 
  am 
  indebted 
  to 
  Mr. 
  Holland, 
  who 
  has 
  '^ne 
  fresh 
  shell, 
  

   the 
  color 
  of 
  which 
  he 
  describes 
  as 
  quoted 
  above, 
  and 
  as 
  faintly 
  

   indicated 
  in 
  the 
  best 
  of 
  the 
  specimens 
  before 
  me. 
  In 
  form 
  it 
  

   approaches 
  more 
  ^nearly 
  to 
  H. 
  ampliata 
  and 
  H. 
  Jamaicensis 
  

   than 
  any 
  of 
  the 
  group, 
  which 
  is 
  characterised 
  by 
  an 
  anterior 
  

   notch 
  or 
  slit 
  in 
  the 
  margin 
  of 
  the 
  aperture. 
  

  

  I 
  am 
  indebted 
  to 
  Mr. 
  Holland 
  for 
  a 
  variety 
  of 
  Helicina 
  

   depressa 
  of 
  extraordinary 
  size. 
  Its 
  mean 
  divergence 
  is 
  140° 
  ; 
  

   greatest 
  breadth 
  .33 
  inch 
  ; 
  least 
  breadth 
  .28 
  inch 
  ; 
  height 
  .18 
  

   inch. 
  The 
  corresponding 
  dimensions 
  of 
  an 
  ordinary 
  specimen 
  

   are 
  140° 
  ; 
  .24 
  inch 
  ; 
  .2 
  inch 
  ; 
  .125 
  inch. 
  It 
  may 
  be 
  designa- 
  

   ted 
  by 
  the 
  name 
  of 
  valida. 
  

  

  A 
  variety 
  of 
  Trochatella 
  Josephince, 
  from 
  the 
  western 
  part 
  

   of 
  the 
  island, 
  presents 
  a 
  type 
  quite 
  distinct 
  from 
  that 
  which 
  

   served 
  for 
  the 
  description 
  of 
  the 
  species, 
  and 
  which 
  inhabit 
  

   the 
  eastern 
  part. 
  The 
  spiral 
  ridges 
  are 
  less 
  conspicuous, 
  and 
  

   are 
  more 
  or 
  less 
  interrupted 
  by 
  various 
  irregularities 
  of 
  the 
  

   surface. 
  The 
  acute 
  periphery 
  is 
  furnished 
  with 
  very 
  promi- 
  

   nent 
  vaulted 
  Compressed 
  scales, 
  and 
  is 
  of 
  a 
  red 
  color. 
  The 
  

   inferior 
  surface 
  is 
  of 
  a 
  lemon 
  yellow 
  color, 
  and 
  its 
  spiral 
  strise 
  

   are 
  rather 
  indistinct. 
  The 
  lower 
  part 
  of 
  the 
  lip 
  is 
  quite 
  thick. 
  

   This 
  type 
  may 
  be 
  designated 
  by 
  the 
  name 
  of 
  pulchra. 
  Its 
  

   mean 
  divergence 
  is 
  100° 
  ; 
  height 
  .29 
  inch 
  ; 
  greatest 
  breadth 
  

   .52 
  inch 
  ; 
  least 
  breadth 
  .44 
  inch. 
  

  

  Of 
  Trochatella 
  Tankervillii 
  several 
  types 
  appear 
  quite 
  

   distinct 
  in 
  extreme 
  specimens, 
  but 
  graduate 
  into 
  each 
  other 
  

   by 
  innumerable 
  intermediate 
  varieties. 
  In 
  one 
  type, 
  variety 
  

   a, 
  the 
  spiral 
  ridges 
  are 
  stronger, 
  and 
  the 
  other 
  irregularities 
  

   of 
  surface 
  are 
  less 
  developed. 
  The 
  last 
  whorl 
  is 
  more 
  convex 
  

   on 
  both 
  sides 
  of 
  the 
  periphery, 
  which 
  is 
  consequently 
  less 
  acute. 
  

   This 
  variety 
  approximates 
  most 
  nearly 
  to 
  T. 
  pulchella 
  in 
  form 
  

   and 
  size. 
  

  

  