﻿332 
  PllOCKEDINGS 
  OF 
  THU 
  MALACOLOGICAL 
  SOCIETX. 
  

  

  deeply 
  gratified 
  at 
  being 
  allowed 
  to 
  dedicate 
  this 
  peculiar 
  genus 
  to 
  

   ray 
  friend 
  Mr. 
  C. 
  Davies 
  Stierborn, 
  of 
  "Index 
  Animaliura 
  " 
  fame, 
  

   and 
  I 
  apply 
  to 
  the 
  type 
  (and 
  at 
  present 
  only) 
  species 
  the 
  trivial 
  

   name 
  of 
  miralilis, 
  an 
  adjective 
  I 
  deem 
  well 
  applicable 
  to 
  my 
  friend 
  

   also. 
  The 
  nucleus 
  is 
  dextral 
  and 
  glassy, 
  consisting 
  of 
  one 
  and 
  a 
  half 
  

   whorls, 
  succeeded 
  by 
  strong 
  rounded 
  spiral 
  lirse 
  which 
  develop 
  

   nodules 
  in 
  some 
  instances 
  : 
  the 
  interstices 
  are 
  plain 
  and 
  there 
  appears 
  

   to 
  be 
  no 
  longitudinal 
  sculpture. 
  The 
  figures 
  given 
  show 
  the 
  

   peculiarities 
  of 
  the 
  shell 
  better 
  than 
  a 
  long 
  description. 
  The 
  

   peculiar 
  specific 
  features 
  cannot 
  be 
  determined 
  until 
  congeners 
  are 
  

   recognized. 
  The 
  specimens 
  are 
  dead 
  shells 
  and 
  pure 
  white, 
  -which 
  

   seems 
  to 
  be 
  the 
  normal 
  coloration. 
  The 
  complete 
  immature 
  shell 
  

   measures 
  about 
  2 
  mm. 
  in 
  length, 
  while 
  the 
  adult 
  measures 
  about 
  

   3 
  mm. 
  long; 
  in 
  breadth 
  the 
  platform 
  increases 
  the 
  shell 
  from 
  

   about 
  1 
  mm. 
  to 
  2-5 
  mm. 
  The 
  tubular 
  apertures 
  present 
  features 
  of 
  

   importance, 
  though 
  the 
  accessory 
  small 
  tube 
  puzzles 
  the 
  student 
  as 
  

   to 
  its 
  function. 
  From 
  criticism 
  of 
  many 
  of 
  the 
  Trituba 
  group 
  of 
  

   Triphoroids 
  I 
  am 
  convinced 
  they 
  are 
  parasitic 
  upon 
  living 
  organisms 
  

   and 
  use 
  the 
  tubes 
  for 
  circulatory 
  purposes. 
  The 
  present 
  genus 
  

   appears 
  to 
  have 
  developed 
  a 
  plate 
  in 
  order 
  to 
  secure 
  itself 
  to 
  its 
  

   host, 
  but 
  wliat 
  the 
  latter 
  may 
  be 
  I 
  cannot 
  at 
  present 
  suggest: 
  

   perhaps 
  it 
  is 
  some 
  quickly 
  moving 
  object. 
  

  

  PiCKWORTiiiA 
  KiRKPATRicKi, 
  gcn. 
  ct 
  sp. 
  nov. 
  (PI. 
  XIII, 
  Fig. 
  6.) 
  

  

  Shell 
  small, 
  turreted, 
  elongate 
  triangular, 
  base 
  flattened, 
  non- 
  

   umbilicate, 
  mouth 
  small, 
  circular, 
  surrounded 
  by 
  a 
  very 
  heavy 
  varix. 
  

   This 
  new 
  genus 
  I 
  also 
  consider 
  representative 
  of 
  a 
  new 
  family 
  

   Pickworthiidae, 
  which 
  may 
  be 
  placed 
  alongside 
  the 
  Liotiidfe, 
  but 
  

   as 
  in 
  the 
  case 
  of 
  the 
  genus 
  just 
  described 
  I 
  would 
  emphasize 
  my 
  

   inability 
  to 
  pronounce 
  exactly 
  on 
  its 
  correct 
  association.. 
  It 
  might 
  

   be 
  compared 
  to 
  a 
  turreted 
  Liotina, 
  but 
  really 
  this 
  would 
  be 
  only 
  

   a 
  fanciful 
  resemblance. 
  

  

  Type 
  : 
  Pichvorthia 
  kirl^patrichi, 
  sp. 
  nov. 
  

  

  The 
  apical 
  whorls 
  are 
  minute, 
  smooth, 
  and 
  three 
  in 
  number; 
  the 
  

   adult 
  whorls 
  are 
  sculptured 
  with 
  nodules, 
  not 
  arranged 
  longi- 
  

   tudinally; 
  the 
  base 
  is 
  very 
  flattened, 
  and 
  no 
  longitudinal 
  sculpture 
  

   is 
  present. 
  There 
  is 
  no 
  umbilicus, 
  but 
  an 
  umbilical 
  depression 
  is 
  

   observed 
  bounded 
  by 
  a 
  thick 
  revolving 
  spiral. 
  The 
  sculptured 
  

   whorls 
  are 
  seven 
  in 
  number. 
  

  

  The 
  nodules 
  appear 
  in 
  two 
  rows 
  to 
  the 
  whorl, 
  an 
  intervening 
  

   depression 
  separating 
  the 
  rows; 
  the 
  suture 
  between 
  the 
  whorls 
  is 
  

   deep 
  and 
  marked 
  ; 
  the 
  number 
  of 
  nodules 
  to 
  the 
  whorl 
  varies 
  from 
  

   twelve 
  in 
  the 
  earlier 
  to 
  fifteen 
  in 
  tlie 
  later 
  ones. 
  

  

  There 
  is 
  no 
  coloration 
  present, 
  the 
  shell 
  being 
  white, 
  vitreous, 
  and 
  

   solid. 
  The 
  periphery 
  of 
  the 
  last 
  whorl 
  develops 
  a 
  flange-like 
  process, 
  

   and 
  the 
  nodulous 
  sculpture 
  becomes 
  obsolete 
  as 
  the 
  aperture 
  is 
  

   reached, 
  while 
  on 
  this 
  last 
  whorl 
  a 
  minor 
  nodulous 
  thread 
  appears 
  

   between 
  the 
  two 
  major 
  rows. 
  The 
  base 
  is 
  flat, 
  a 
  revolving 
  thread 
  

   below 
  the 
  peripheral 
  flange 
  being 
  succeeded 
  by 
  a 
  revolving 
  spiral 
  

   rib 
  which 
  runs 
  round 
  the 
  one 
  bounding 
  the 
  umbilical 
  region. 
  The 
  

  

  