﻿436 
  Panama 
  Shells. 
  cyclostomid^. 
  

  

  315. 
  Auricula 
  trilineata. 
  Nov. 
  sp. 
  

  

  Shell 
  obovate 
  : 
  dark 
  brownish 
  red, 
  with 
  three 
  revolving 
  dis- 
  

   tant 
  white 
  lines 
  on 
  the 
  last 
  whorl, 
  of 
  which 
  the 
  anterior 
  line 
  is 
  

   not 
  so 
  well 
  defined 
  : 
  rufous 
  on 
  the 
  columella 
  : 
  with 
  irregular 
  

   striae 
  of 
  growth 
  : 
  apex 
  obtuse 
  ? 
  spire 
  very 
  small, 
  with 
  the 
  out- 
  

   lines 
  curvilinear: 
  whorls 
  ,* 
  very 
  narrow, 
  imbricately 
  

  

  appressed, 
  with 
  the 
  suture 
  distinct 
  : 
  last 
  whorl 
  very 
  large, 
  con- 
  

   volate 
  : 
  aperture 
  very 
  long, 
  narrow 
  : 
  labrum 
  not 
  sharp, 
  with 
  a 
  

   deposit 
  over 
  the 
  whole 
  visible 
  interior, 
  which 
  is 
  transversely 
  

   plaited 
  : 
  at 
  the 
  end 
  of 
  the 
  columella 
  with 
  a 
  twisted 
  plait, 
  sepa- 
  

   rated 
  by 
  a 
  sinus 
  from 
  a 
  large 
  transverse 
  plait, 
  above 
  which 
  are 
  

   four 
  small 
  approximate 
  transverse 
  plaits. 
  

  

  Mean 
  divergence 
  about 
  135° 
  ; 
  length 
  .71 
  inch 
  ; 
  breadth 
  .43 
  

   inch 
  ; 
  length 
  of 
  spire 
  .05 
  inch. 
  

  

  Station. 
  — 
  Unknown. 
  

  

  Habitat 
  — 
  Panama 
  ; 
  C. 
  B. 
  A. 
  ! 
  

   Only 
  1 
  specimen 
  was 
  found. 
  

  

  316. 
  Auricula 
  • 
  Sp. 
  indet. 
  

  

  Station. 
  — 
  Under 
  stones 
  at 
  high 
  water 
  mark. 
  

  

  Habitat 
  — 
  Panama 
  ; 
  C. 
  B. 
  A. 
  ! 
  

  

  We 
  obtained 
  2 
  specimens, 
  which, 
  although 
  immature, 
  appear 
  

   distinct 
  from 
  the 
  other 
  species 
  of 
  Auricula. 
  

  

  Family— 
  CYCLOSTOMID^. 
  

  

  TRriVCATELLA.— 
  We 
  include 
  this 
  genus, 
  as 
  well 
  as 
  

   Pedipes 
  and 
  Auricula^ 
  in 
  this 
  paper, 
  because 
  they 
  are 
  maritime 
  

   in 
  their 
  habits. 
  Their 
  geographical 
  distribution, 
  corresponding 
  

   with 
  that 
  of 
  the 
  marine 
  genera, 
  is 
  entirely 
  different 
  from 
  that 
  of 
  

   the 
  terrestrial 
  molluscs. 
  

  

  * 
  In 
  our 
  unique 
  specimen 
  the 
  sutui-e 
  of 
  the 
  upper 
  whorls 
  is 
  obliterated 
  by 
  ero- 
  

   sion. 
  Probably 
  the 
  number 
  of 
  whorls 
  is 
  six 
  or 
  seven. 
  

  

  