﻿60 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol.98 
  

  

  There 
  is 
  considerable 
  variation 
  in 
  its 
  shape 
  among 
  males 
  from 
  the 
  same 
  

   locality, 
  ranging 
  from 
  a 
  simple, 
  flattened, 
  tapering 
  cylinder 
  to 
  a 
  prong 
  

   with 
  a 
  "meat-chopper" 
  blade 
  on 
  one 
  side 
  (see 
  pi. 
  3, 
  fig. 
  6, 
  a-d) 
  . 
  Mantle 
  

   of 
  animal 
  thin, 
  with 
  a 
  slightly 
  thickened 
  border. 
  The 
  gills 
  or 
  ctenidia 
  

   consist 
  of 
  a 
  series 
  of 
  27 
  to 
  29 
  low, 
  narrow 
  lamellae 
  or 
  platelike 
  flesh 
  

   folds 
  attached 
  to 
  the 
  inner 
  side 
  of 
  the 
  mantle. 
  

  

  Color: 
  In 
  general 
  a 
  dark 
  blackish 
  gray. 
  The 
  most 
  distinguishing 
  

   color 
  markings 
  are 
  the 
  bright 
  splotching 
  of 
  yellow 
  or 
  yellowish-white 
  

   granularlike 
  dots 
  over 
  each 
  eye, 
  forming 
  false 
  "eyebrows." 
  Under- 
  

   side 
  of 
  foot 
  light 
  slate-gray, 
  peppered 
  with 
  minute 
  white 
  dots. 
  Ten- 
  

   tacles 
  sandy 
  brown 
  to 
  gray 
  with 
  a 
  clear, 
  colorless 
  rim. 
  Proboscis 
  gray 
  

   to 
  gray-brown, 
  with 
  a 
  narrow, 
  clear 
  rim 
  on 
  the 
  anterior 
  edge. 
  The 
  

   penis 
  at 
  its 
  base 
  is 
  dusted 
  with 
  black 
  specks, 
  the 
  remainder 
  being 
  a 
  

   translucent 
  yellowish 
  gray. 
  

  

  The 
  animal 
  of 
  the 
  species 
  is 
  very 
  similar 
  to 
  Oncomelama 
  nosophora 
  

   (Robson) 
  and 
  O. 
  hupensis 
  Gredler. 
  Previous 
  accounts 
  of 
  the 
  divided 
  

   foot 
  and 
  loping 
  locomotion 
  of 
  Pomatiopsis 
  are 
  misleading. 
  When 
  

   crawling 
  out 
  of 
  water 
  the 
  animals 
  of 
  Oncomelania 
  and 
  Pomatiopsis 
  

   have 
  the 
  same 
  type 
  of 
  motion, 
  and 
  both 
  produce 
  folds 
  in 
  the 
  flesh 
  of 
  

   the 
  foot 
  due 
  to 
  the 
  weight 
  of 
  the 
  shell 
  and 
  body. 
  In 
  Poinatwpsis 
  this 
  

   is 
  accentuated 
  to 
  such 
  a 
  degree 
  that 
  the 
  foot 
  appears 
  divided. 
  When 
  

   immersed 
  in 
  water 
  the 
  folds 
  disappear 
  and 
  locomotion 
  is 
  accomplished 
  

   by 
  gliding. 
  The 
  penis 
  in 
  Onconwlania 
  is 
  constantly 
  a 
  simple 
  prong, 
  

   while 
  in 
  Pomatiopsis 
  a 
  number 
  of 
  simple 
  variations 
  of 
  this 
  type 
  are 
  

   expressed 
  in 
  the 
  form 
  of 
  side 
  blades. 
  

  

  The 
  yellow 
  "eyebrows" 
  in 
  Oncortxelania 
  decrease 
  in 
  size 
  and 
  bright- 
  

   ness 
  the 
  farther 
  north 
  the 
  habitat. 
  The 
  yellowest 
  and 
  largest 
  "eye- 
  

   brows" 
  are 
  found 
  in 
  O. 
  quadrasi 
  (Mollendorff) 
  of 
  the 
  Philippines, 
  

   with 
  those 
  of 
  O. 
  for-mosana 
  (Pilsbry 
  and 
  Hirase) 
  of 
  Formosa, 
  0. 
  

   hupensis 
  of 
  China, 
  and 
  O. 
  nosophora 
  of 
  China 
  and 
  Japan 
  becoming 
  

   progressively 
  whiter 
  and 
  smaller. 
  Pomatiopsis 
  lapidaria 
  individuals 
  

   from 
  one 
  colony 
  express 
  variation 
  from 
  almost 
  no 
  "eyebrow" 
  coloring 
  

   through 
  distinctly 
  yellow 
  to 
  a 
  whitish 
  yellow. 
  This 
  latter 
  color 
  is 
  

   fairly 
  common 
  in 
  a 
  colony 
  of 
  living 
  O. 
  nosophora 
  examined 
  from 
  

   Kurume, 
  Chikugo 
  Province, 
  Kyushu 
  Island, 
  Japan. 
  

  

  The 
  reproductive, 
  nervous, 
  and 
  digestive 
  systems 
  of 
  the 
  two 
  genera 
  

   show 
  few 
  differences. 
  Drawings 
  of 
  the 
  central 
  nervous 
  system 
  of 
  

   Pomatiopsis 
  lajyidarla 
  (Say) 
  and 
  Oncomelama 
  hupensis 
  Gredler 
  are 
  

   included. 
  The 
  latter 
  was 
  indaequately 
  figured 
  by 
  Heude 
  in 
  1882, 
  and 
  

   since 
  Annandale 
  (1924) 
  attempted 
  to 
  compare 
  it 
  with 
  other 
  Oncome- 
  

   lania 
  for 
  systematic 
  purposes, 
  we 
  are 
  recording 
  our 
  findings 
  to 
  show 
  

   that 
  no 
  significant 
  difference 
  of 
  taxonomic 
  importance 
  can 
  be 
  found 
  

   between 
  the 
  two 
  genera. 
  The 
  central 
  nervous 
  systems 
  of 
  Oncomelania 
  

   quadrasi 
  figured 
  by 
  Abbott 
  (1945), 
  O. 
  nosophora 
  (Robson), 
  and 
  0. 
  

   hupensis 
  are 
  almost 
  identical. 
  

  

  