﻿REVIEW 
  OF 
  THE 
  ATLANTIC 
  PERIWINKLES 
  — 
  ABBOTT 
  459 
  

  

  Litorina 
  (Tectarius) 
  pfeifferianus 
  Weinkauff 
  (new 
  name 
  for 
  Littorina 
  nodulosa 
  

   Pfeiffer, 
  non 
  Littorina 
  nodulosa 
  Gmelin 
  of 
  authors), 
  Litorina, 
  in 
  Martini 
  

   and 
  Chemnitz, 
  SystematischesConchyhen- 
  Cabinet, 
  vol. 
  2, 
  pt. 
  9, 
  p. 
  46, 
  pi. 
  5, 
  

   figs. 
  15, 
  16, 
  1882. 
  

  

  Shell. 
  — 
  Perhaps 
  the 
  most 
  distinctive 
  feature 
  of 
  the 
  shell 
  of 
  this 
  

   species 
  is 
  the 
  nature 
  of 
  the 
  rows 
  of 
  nodules. 
  As 
  in 
  Nodilittorina 
  

   tuberculata, 
  the 
  periphery 
  of 
  the 
  last 
  whorl 
  bears 
  two 
  prominent 
  rows 
  

   of 
  large 
  nodules, 
  thus 
  giving 
  the 
  shell 
  a 
  slightly 
  bicarinate 
  appearance. 
  

   There 
  are 
  five 
  or 
  six 
  minor 
  rows 
  of 
  smaller 
  beads. 
  But 
  especially 
  

   notable 
  in 
  Echininus 
  are 
  the 
  fewer 
  and 
  larger 
  nodules 
  in 
  the 
  upper 
  

   major 
  row. 
  A 
  count 
  in 
  30 
  specimens 
  revealed 
  that, 
  on 
  the 
  average, 
  

   there 
  are 
  3 
  or 
  4 
  fewer 
  nodules 
  in 
  the 
  upper 
  row. 
  No 
  significant 
  differ- 
  

   ence 
  in 
  this 
  feature 
  could 
  be 
  found 
  between 
  the 
  males 
  and 
  the 
  females. 
  

   (In 
  15 
  males, 
  the 
  upper 
  row, 
  on 
  the 
  average, 
  bore 
  11.3 
  nodules 
  with 
  a 
  

   range 
  of 
  9 
  to 
  14; 
  the 
  lower 
  row 
  had 
  14.9 
  nodules 
  with 
  a 
  range 
  of 
  11 
  to 
  

   17. 
  In 
  15 
  females, 
  the 
  upper 
  row 
  bore 
  10.9 
  nodules 
  with 
  a 
  range 
  of 
  

   9 
  to 
  13; 
  the 
  lower 
  row 
  bore 
  13.0 
  nodules 
  with 
  a 
  range 
  of 
  10 
  to 
  15.) 
  

  

  Measurements 
  of 
  shell 
  length 
  were 
  compared 
  between 
  18 
  adult 
  

   males 
  and 
  21 
  females, 
  and 
  it 
  was 
  found 
  that 
  there 
  is 
  a 
  slight 
  sexual 
  

   dimorphism 
  in 
  which 
  the 
  mean 
  length 
  of 
  males 
  is 
  13 
  mm. 
  and 
  that 
  of 
  

   the 
  females 
  15 
  mm. 
  The 
  overlap 
  in 
  shell 
  size, 
  however, 
  is 
  too 
  great 
  

   to 
  permit 
  distinction 
  of 
  sex 
  on 
  this 
  character 
  alone. 
  

  

  I 
  notice 
  that 
  the 
  shells 
  of 
  some 
  of 
  the 
  females 
  are 
  more 
  eroded 
  than 
  

   those 
  of 
  the 
  males, 
  and 
  in 
  this 
  connection 
  there 
  is 
  need 
  for 
  fm'ther 
  

   study 
  on 
  the 
  wanderings 
  of 
  the 
  females 
  and 
  their 
  possible 
  subjection 
  

   to 
  conditions 
  slightly 
  different 
  from 
  the 
  males. 
  M. 
  Lebour 
  (1945) 
  

   believes 
  that 
  the 
  amphibious 
  Littorinids 
  of 
  Bermuda 
  seasonally 
  

   descend 
  from 
  their 
  positions 
  high 
  in 
  trees 
  or 
  from 
  rock 
  cliffs 
  to 
  the 
  

   edge 
  of 
  the 
  ocean 
  to 
  deposit 
  their 
  eggs. 
  Whether 
  the 
  males 
  also 
  

   migrate 
  is 
  unknown. 
  

  

  Animal. 
  — 
  Our 
  studies 
  were 
  made 
  on 
  living 
  specimens 
  from 
  Rincon 
  

   Lighthouse, 
  western 
  Puerto 
  Rico. 
  The 
  animal 
  is 
  typically 
  littorinid, 
  

   as 
  discussed 
  under 
  the 
  remarks 
  concerning 
  the 
  subgenus. 
  The 
  mantle 
  

   edge 
  is 
  smooth, 
  slightly 
  swollen, 
  and 
  yellowish; 
  the 
  remamder 
  is 
  clear. 
  

   The 
  underside 
  of 
  the 
  foot 
  is 
  yellowish 
  gray, 
  but 
  not 
  as 
  yellow 
  as 
  in 
  

   Nodilittorina. 
  The 
  longitudinal 
  fissure 
  on 
  the 
  sole 
  of 
  the 
  foot 
  is 
  very 
  

   weak 
  and 
  limited 
  to 
  the 
  posterior 
  half. 
  The 
  retrograde 
  (front 
  to 
  

   back) 
  waves 
  at 
  the 
  anterior 
  thu"d 
  of 
  the 
  sole 
  are 
  usually 
  several 
  and 
  

   somewhat 
  confused, 
  but 
  as 
  they 
  proceed 
  posterior 
  and 
  reach 
  the 
  

   region 
  of 
  the 
  weak, 
  central 
  fissure, 
  they 
  become 
  stronger 
  and 
  take 
  on 
  

   a 
  ditaxic, 
  lateral 
  division. 
  

  

  The 
  penis 
  is 
  large, 
  promment, 
  and 
  located 
  on 
  the 
  right 
  side 
  of 
  the 
  

   body 
  of 
  the 
  males. 
  The 
  accessory 
  flagellum 
  is 
  cylindrical, 
  larger 
  than 
  

   that 
  found 
  in 
  Nodilittorina, 
  and 
  located 
  one-third 
  from 
  the 
  distal 
  end 
  

  

  