﻿238 
  PROCEEDINGS 
  OE 
  THE 
  MALACOLOGICAL 
  SOCIETY. 
  

  

  than 
  in 
  P. 
  vespertina. 
  The 
  pedis 
  elevator 
  (Fig. 
  11, 
  E.P.) 
  is 
  more 
  

   central. 
  

  

  Alimentary 
  Canal. 
  — 
  The 
  lips 
  (Figs. 
  11, 
  12, 
  and 
  13, 
  A.L. 
  and 
  P.L.) 
  

   project 
  forwardly. 
  The 
  oesophagus 
  (Figs. 
  12 
  and 
  13, 
  Oe.) 
  is 
  long 
  

   and 
  comparatively 
  narrow. 
  It 
  runs 
  directly 
  backwards 
  to 
  the 
  

   oesophageal 
  division 
  (Fig. 
  12, 
  Oe.St.) 
  of 
  the 
  stomach, 
  the 
  latter 
  being 
  

   small 
  and 
  bordered 
  at 
  the 
  rear 
  end 
  by 
  a 
  conspicuous 
  process 
  of 
  the 
  wall 
  

   of 
  the 
  stomach 
  (Fig. 
  12, 
  IT.P.), 
  a 
  continuation 
  of 
  which 
  separates 
  the 
  

   oesophageal 
  from 
  the 
  cardiac, 
  central, 
  and 
  pyloric 
  divisions. 
  The 
  cardiac 
  

   division 
  (Fig. 
  12, 
  C.St.) 
  is 
  likewise 
  small, 
  and 
  so 
  is 
  the 
  central 
  division 
  

   (Fig. 
  12, 
  C.B.). 
  The 
  pyloric 
  division 
  (Figs. 
  12 
  and 
  13, 
  P.St.) 
  is 
  

   very 
  large, 
  and, 
  on 
  its 
  ventral 
  side, 
  opens 
  into 
  the 
  caecum 
  of 
  the 
  

   crj'stalline 
  style 
  (Figs. 
  12 
  and 
  13, 
  C.C.). 
  The 
  cpecum 
  is 
  long 
  and 
  

   extends 
  in 
  a 
  ventral 
  direction. 
  On 
  the 
  right 
  side 
  of 
  it 
  is 
  the 
  intestine, 
  

   appearing 
  as 
  a 
  narrow 
  groove. 
  At 
  the 
  distal 
  end 
  the 
  intestine 
  

   becomes 
  free, 
  and 
  passes 
  dorsally 
  until 
  over 
  the 
  pyloric 
  division, 
  

   where 
  it 
  makes 
  a 
  number 
  of 
  folds, 
  goes 
  posteriorly 
  over 
  the 
  posterior 
  

   adductor 
  muscle, 
  and 
  terminates 
  in 
  a 
  simple 
  slightly 
  projecting 
  anus 
  

   on 
  the 
  postero-ventral 
  side 
  of 
  the 
  muscle. 
  

  

  In 
  the 
  branchia 
  the 
  plicae 
  have 
  in 
  the 
  inner 
  demibranch 
  from 
  

   17-21 
  filaments, 
  and 
  in 
  the 
  outer 
  from 
  14-17 
  filaments. 
  The 
  

   principal 
  filament 
  is 
  very 
  shallow. 
  

  

  PSAMMOBIA 
  COSTULATA, 
  TurtoU. 
  

  

  Only 
  one 
  animal 
  has 
  been 
  examined, 
  and 
  it 
  measures 
  14 
  mm. 
  by 
  

   7 
  mm. 
  The 
  dorsal 
  surface 
  is 
  not 
  quite 
  so 
  curved 
  as 
  in 
  P. 
  tellmella, 
  

   but 
  the 
  ventral 
  part 
  is 
  deeper, 
  otherwise 
  the 
  mantle-lobes 
  in 
  the 
  

   distribution 
  of 
  the 
  pallial 
  muscles 
  and 
  the 
  characters 
  of 
  the 
  longi- 
  

   tudinal 
  folds 
  are 
  similar. 
  

  

  The 
  anterior 
  adductor 
  muscle 
  (Fig. 
  14, 
  A. 
  A.) 
  is 
  like 
  that 
  of 
  

   P. 
  tellmella, 
  with 
  the 
  exception 
  that 
  the 
  postero-ventral 
  part 
  is 
  

   laterally 
  a 
  little 
  more 
  compressed. 
  The 
  posterior 
  adductor 
  muscle 
  

   (Fig. 
  14, 
  P. 
  A.), 
  which 
  is 
  situated 
  more 
  posteriorly 
  than 
  in 
  P. 
  tellinella, 
  

   is 
  also 
  similar 
  in 
  shape, 
  but 
  the 
  ends 
  are 
  flatter, 
  as 
  the 
  portion 
  of 
  

   the 
  shell 
  to 
  which 
  it 
  adheres 
  is 
  not 
  so 
  curved, 
  and 
  further 
  the 
  

   surface 
  is 
  ribbed, 
  corresponding 
  with 
  the 
  ribbings 
  of 
  the 
  shell. 
  

  

  A. 
  anus 
  ; 
  A. 
  A. 
  anterior 
  adductor 
  muscle 
  ; 
  A.In. 
  ascending 
  intestine; 
  A.L. 
  

   anterior 
  or 
  upper 
  lip 
  ; 
  C.G. 
  eeecum 
  of 
  the 
  crystalline 
  style 
  ; 
  CD. 
  central 
  division 
  

   of 
  the 
  stomach; 
  C.P.C. 
  eerebro-pedal 
  connective; 
  C.P.G. 
  cerebro-pleural 
  

   ganglion; 
  C.St, 
  cardiac 
  division 
  of 
  the 
  stomach; 
  C.V.G. 
  cerebro-visceral 
  

   connective 
  ; 
  D.G. 
  digestive 
  gland 
  or 
  liver 
  ; 
  D.M.G. 
  duct 
  of 
  mucus 
  gland 
  ; 
  

   E.P. 
  elevator 
  pedis 
  muscle; 
  Ep.G. 
  epithelial 
  cells; 
  Ep.Gol. 
  columnar 
  

   epithelium; 
  Ex.S. 
  exhalent 
  siphonal 
  tube; 
  jP. 
  foot 
  ; 
  In. 
  intestine; 
  Bi.S. 
  

   inhalent 
  siphonal 
  tube 
  ; 
  M. 
  mouth 
  ; 
  M.G. 
  musculus 
  cruciformis 
  ; 
  M.G. 
  mucus 
  

   gland; 
  M.P. 
  prominent 
  process 
  of 
  the 
  gastric 
  wall 
  ; 
  Oe. 
  oesophagus 
  ; 
  Oe.St. 
  

   oesophageal 
  division 
  of 
  the 
  stomach 
  ; 
  P. 
  A. 
  posterior 
  adductor 
  muscle 
  ; 
  P.G. 
  

   pedal 
  ganglion 
  ; 
  P.L. 
  posterior 
  or 
  lower 
  lip 
  ; 
  P.L. 
  P. 
  posterior 
  portion 
  of 
  the 
  

   mantle-lobe; 
  P.P. 
  protractor 
  pedis 
  muscle; 
  P.R.A. 
  retractor 
  pedis 
  anterior 
  

   muscle 
  ; 
  P. 
  Pi. 
  P. 
  retractor 
  pedis 
  posterior 
  muscle 
  ; 
  P.St, 
  pyloric 
  division 
  of 
  the 
  

   stomach 
  ; 
  R. 
  rectum 
  ; 
  S.R.M. 
  siphonal 
  retractor 
  muscle 
  ; 
  St. 
  stomach 
  ; 
  

   Ty. 
  typhlosole 
  ; 
  V. 
  ventricle 
  ; 
  V.P.G. 
  viscero-parietal 
  ganglion. 
  

  

  