﻿PROCEEDINGS 
  OF 
  THE 
  UNITED 
  STATES 
  NATIONAL 
  MUSEUM 
  

  

  issued 
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  SMITHSONIAN 
  INSTITUTION 
  

   U. 
  S. 
  NATIONAL 
  MUSEUM 
  

  

  Vol. 
  103 
  Washington: 
  1954 
  No. 
  3328 
  

  

  REVIEW 
  OF 
  THE 
  ATLANTIC 
  PERIWINKLES, 
  

   NODILITTORINA, 
  ECHININUS, 
  AND 
  TECTARIUS 
  

  

  By 
  R. 
  Tucker 
  Abbott 
  

  

  Since 
  the 
  1942 
  publication 
  in 
  Johnsonia 
  of 
  "The 
  Genera 
  Tectarius 
  

   and 
  Echininus 
  in 
  the 
  Western 
  Atlantic" 
  by 
  Clench 
  and 
  Abbott, 
  

   enough 
  additional 
  data 
  have 
  been 
  assembled 
  to 
  warrant 
  a 
  review 
  of 
  

   this 
  group 
  of 
  tropical, 
  littoral 
  snails. 
  In 
  addition 
  to 
  the 
  anatomical, 
  

   distributional, 
  and 
  biological 
  information 
  presented 
  here, 
  there 
  is 
  a 
  

   short 
  discussion 
  of 
  the 
  phylogenetic 
  position 
  of 
  the 
  genus 
  Echininus, 
  

   and 
  some 
  changes 
  in 
  nomenclature. 
  

  

  It 
  had 
  been 
  noted 
  for 
  some 
  time 
  that 
  the 
  operculum 
  of 
  Echininus 
  

   was 
  multispiral, 
  a 
  feature 
  commonly 
  found 
  among 
  members 
  of 
  such 
  

   families 
  as 
  the 
  Trochidae, 
  Potamididae, 
  and 
  Modulidae 
  but 
  unusual 
  

   for 
  the 
  Littorinidae, 
  which 
  are 
  well 
  known 
  for 
  their 
  paucispiral 
  

   opercula. 
  In 
  a 
  paper 
  that 
  has 
  generally 
  been 
  overlooked, 
  Kesteven 
  

   (1903) 
  removed 
  the 
  genus 
  Echininus 
  (Echinella 
  of 
  Kesteven) 
  from 
  its 
  

   customary 
  position 
  in 
  the 
  Littorinidae 
  and 
  placed 
  it 
  in 
  the 
  Modulidae. 
  

   This 
  has 
  necessitated 
  our 
  making 
  a 
  study 
  of 
  the 
  gross 
  anatomy 
  of 
  

   Echininus, 
  Tectarius, 
  and 
  Modulus. 
  This 
  study 
  was 
  made 
  possible 
  

   through 
  the 
  generosity 
  of 
  Mrs. 
  Germaine 
  L. 
  Warmke, 
  who 
  collected 
  

   and 
  airmailed 
  living 
  specimens 
  of 
  Echininus 
  nodulosus 
  Pfeiffer 
  and 
  

   Nodilittorina 
  tuber 
  culata 
  Menke 
  from 
  Puerto 
  Rico. 
  In 
  the 
  process 
  

   of 
  comparing 
  the 
  latter 
  species 
  with 
  Tectarius 
  muricatus 
  Linn6, 
  we 
  

   came 
  to 
  the 
  conclusion 
  that 
  Nodilittorina 
  should 
  be 
  considered 
  as 
  a 
  

   full 
  genus 
  closely 
  related 
  to 
  Melarhaphe 
  or 
  Littoraria 
  rather 
  than 
  as 
  a 
  

   subgenus 
  of 
  Tectarius. 
  

  

  The 
  nomenclatorial 
  adjustments 
  in 
  this 
  paper 
  involve 
  changing 
  the 
  

   name 
  used 
  in 
  Johnsonia, 
  Tectarius 
  tuberculatum 
  Wood, 
  to 
  Nodilittorina 
  

   tuberculata 
  Menke, 
  and 
  a 
  new 
  and 
  presumably 
  valid 
  genotype 
  desig- 
  

   nation 
  for 
  Nodilittorina. 
  

  

  278946—54 
  449 
  

  

  