﻿56 
  Analysis 
  of 
  a 
  certain 
  Grotip 
  of 
  Species 
  of 
  Cyclostoma. 
  

  

  transverse 
  ridges 
  cross 
  the 
  spiral 
  ridges 
  with 
  enlargement. 
  

   We 
  propose 
  for 
  it 
  the 
  name 
  of 
  docens, 
  in 
  allusion 
  to 
  its 
  in- 
  

   structiveness 
  on 
  the 
  question 
  of 
  the 
  origin 
  of 
  varieties. 
  

  

  A 
  specimen 
  of 
  Cyclostoma 
  lincina 
  from 
  the 
  mountains 
  

   behind 
  Spanish 
  Town 
  is 
  remarkable 
  for 
  its 
  size 
  and 
  the 
  devel- 
  

   opment 
  of 
  the 
  outer 
  peritreme. 
  Its 
  dimensions 
  are 
  — 
  mean 
  

   divergence 
  54° 
  ; 
  length 
  1 
  inch 
  ; 
  greatest 
  breadth 
  .77 
  inch 
  ; 
  

   least 
  breadth 
  .6 
  inch 
  : 
  transverse 
  diameter 
  of 
  the 
  aperture 
  .3 
  

   inch, 
  and 
  including 
  the 
  peritreme 
  .57 
  inch 
  ! 
  

  

  On 
  pages 
  91 
  and 
  93 
  of 
  Contr. 
  Conch, 
  two 
  varietie 
  sof 
  one 
  

   species 
  were 
  accidentally 
  published 
  as 
  distinct 
  species, 
  with 
  

   the 
  names 
  of 
  C. 
  nodulosum 
  and 
  C. 
  granosum. 
  These 
  varie- 
  

   ties 
  differ 
  slightly. 
  The 
  name, 
  C. 
  granosum, 
  having 
  appeared 
  

   in 
  Mr. 
  Redfield's 
  catalogue, 
  and 
  being 
  rather 
  more 
  appropriate; 
  

   may 
  be 
  adopted 
  to 
  the 
  exclusion 
  of 
  the 
  other. 
  Another 
  vari- 
  

   ety 
  of 
  this 
  species 
  occurs, 
  in 
  which 
  the 
  last 
  whorl 
  is 
  much 
  

   detached 
  from 
  the 
  penult 
  whorl. 
  It 
  is 
  also 
  entirely 
  destitute 
  

   of 
  the 
  purplish 
  brown 
  color 
  anteriorly. 
  The 
  two 
  individuals, 
  

   which 
  we 
  have 
  received 
  on 
  loan 
  from 
  Mr. 
  Chitty, 
  make 
  us 
  

   acquainted 
  with 
  the 
  operculum 
  of 
  this 
  species. 
  It 
  has 
  a 
  spi- 
  

   ral 
  lamella, 
  well 
  elevated, 
  of 
  more 
  than 
  three 
  whorls. 
  The 
  

   variety 
  may 
  be 
  designated 
  by 
  the 
  name 
  of 
  aberrans. 
  

  

  Analysis 
  of 
  the 
  Group 
  of 
  Species 
  of 
  Cyclostoma, 
  which 
  is 
  

   represented 
  by 
  C. 
  Jamaicense 
  Chem. 
  

  

  This 
  group 
  has 
  been 
  more 
  or 
  less 
  known 
  for 
  nearly 
  sixty 
  

   years 
  under 
  the 
  name 
  proposed 
  by 
  Chemnitz. 
  In 
  March, 
  

   1843, 
  Mr. 
  Sowerby, 
  (Proc. 
  Zool. 
  Soc. 
  Lond. 
  and 
  Thes. 
  Conch. 
  

   I. 
  p. 
  95, 
  pi. 
  23, 
  f. 
  10, 
  11,) 
  described 
  a 
  second 
  species 
  under 
  the 
  

   name 
  of 
  C. 
  corrugatum. 
  Both 
  species 
  have 
  been 
  repeated 
  

   by 
  Dr. 
  PfeifFer 
  in 
  Kuster's 
  Cyclostomacea. 
  During 
  the 
  pres- 
  

  

  