﻿74 
  PKOE. 
  P. 
  M. 
  DUNCAN 
  ON 
  THE 
  GENUS 
  STOLICZKJLRIA. 
  

  

  here 
  and 
  there 
  a 
  tubular 
  form, 
  are 
  much 
  smaller 
  than 
  the 
  radial 
  tubes, 
  

   around 
  which 
  they 
  sometimes, 
  but 
  not 
  invariably, 
  reach. 
  Hence 
  

   in 
  tangential 
  sections 
  the 
  stellate 
  appearance 
  presented 
  by 
  Stolicz- 
  

   Tcaria 
  is 
  due 
  to 
  a 
  number 
  of 
  circle-systems, 
  each 
  of 
  which 
  has 
  a 
  centre 
  

   containing 
  the 
  cut 
  ends 
  of 
  many 
  small 
  tubes, 
  and 
  of 
  an 
  environing 
  

   circle 
  of 
  sections 
  of 
  much 
  larger 
  tubes, 
  all 
  intercommunicating. 
  And 
  

   in 
  ParJceria 
  the 
  irregular 
  appearance 
  of 
  canals 
  in 
  similar 
  sections 
  is 
  

   due 
  to 
  sections 
  of 
  large 
  radial 
  tubes, 
  one 
  in 
  each 
  circle, 
  each 
  tube 
  

   being 
  surrounded 
  by 
  much 
  smaller 
  and 
  irregularly 
  shaped 
  sections 
  

   of 
  cells 
  and 
  labyrinthic 
  structure. 
  

  

  In 
  StoliczJcaria 
  the 
  interspaces 
  are 
  not 
  universal 
  ; 
  and 
  careful 
  ob- 
  

   servations 
  tend 
  to 
  the 
  belief 
  that 
  they 
  have 
  nothing 
  to 
  do 
  with 
  the 
  

   primary 
  condition 
  of 
  the 
  body, 
  and 
  that 
  many 
  depend 
  upon 
  the 
  pro- 
  

   cess 
  of 
  fossilization, 
  and 
  the 
  rest 
  upon 
  the 
  method 
  of 
  growth 
  of 
  the 
  

   tubular 
  structures. 
  

  

  In 
  fact 
  the 
  Syringosphaeridae 
  are 
  composed 
  of 
  tubes 
  starting 
  from 
  

   the 
  centre 
  of 
  a 
  body 
  and 
  radiating 
  to 
  the 
  circumference, 
  without 
  any 
  

   Foraminiferai 
  structure. 
  The 
  tubes 
  are 
  of 
  two 
  kinds 
  : 
  — 
  one 
  which 
  

   leads 
  a 
  straight 
  course, 
  and 
  whose 
  calibre 
  is 
  small 
  ; 
  and 
  the 
  other 
  

   is 
  intermediate, 
  highly 
  convolute, 
  and 
  the 
  calibre 
  is 
  larger. 
  

  

  Clearly 
  the 
  Syringosphseridse 
  formed 
  the 
  calcareous 
  tubes 
  organi- 
  

   cally, 
  and 
  they 
  are 
  not 
  comparable 
  with 
  arenaceous 
  Foraminifera. 
  

  

  EXPLANATION 
  OF 
  PLATE 
  II. 
  

  

  Fig. 
  1. 
  The 
  granulations 
  on 
  the 
  surface 
  of 
  StoliczJcaria 
  granulata, 
  Dune, 
  

   magnified 
  45 
  cliam. 
  

  

  2. 
  A 
  tangential 
  section, 
  magnified 
  50 
  diain. 
  

  

  3. 
  A 
  radial 
  section, 
  magnified 
  50 
  diani. 
  

  

  r 
  " 
  I 
  Interradial 
  tubes, 
  magnified 
  100 
  diam. 
  

  

  6. 
  A 
  diagram 
  of 
  the 
  disposition 
  of 
  the 
  tubular 
  structures, 
  nat. 
  size. 
  

  

  Discussion. 
  

  

  Prof. 
  Seeley 
  thought 
  that 
  the 
  difference 
  between 
  StoliczJcaria 
  and 
  

   ParJceria 
  was 
  one 
  of 
  mode 
  of 
  growth 
  rather 
  than 
  of 
  structure. 
  He 
  

   felt 
  doubt 
  as 
  to 
  the 
  affinities 
  of 
  these 
  organisms. 
  He 
  was 
  inclined 
  

   to 
  regard 
  ParJceria 
  as 
  showing 
  affinities 
  both 
  with 
  the 
  Sponges 
  and 
  

   the 
  Foraminifera. 
  He 
  thought 
  that 
  the 
  analysis 
  of 
  StoliczJcaria 
  

   served 
  to 
  throw 
  doubt 
  on 
  the 
  conclusion 
  that 
  ParJceria 
  was 
  originally 
  

   composed 
  of 
  phosphatic 
  grains. 
  He 
  was 
  inclined 
  to 
  believe 
  that 
  

   both 
  StoliczJcaria 
  and 
  ParTceria 
  were 
  originally 
  calcareous 
  organisms. 
  

  

  Mr. 
  Tawney 
  asked 
  if 
  Dr. 
  Duncan 
  had 
  considered 
  the 
  possible 
  

   alliance 
  of 
  these 
  fossils 
  with 
  Hydractinia. 
  

  

  The 
  Author 
  admitted 
  that 
  it 
  was 
  a 
  difficult 
  question 
  whether 
  

   ParJceria 
  was 
  originally 
  calcareous 
  or 
  phosphatic. 
  With 
  regard 
  to 
  

   its 
  zoological 
  position, 
  it 
  differed 
  from 
  sponges 
  in 
  having 
  no 
  spicules, 
  

   and 
  had 
  little 
  in 
  common 
  with 
  any 
  of 
  the 
  known 
  forms 
  of 
  sponge. 
  

   With 
  regard 
  to 
  affinities 
  with 
  the 
  hydroids, 
  in 
  spite 
  of 
  superficial 
  

   resemblances 
  there 
  were 
  remarkable 
  differences. 
  He 
  did 
  not 
  place 
  

   these 
  forms 
  among 
  the 
  Foraminifera 
  ; 
  but 
  he 
  regarded 
  them 
  as 
  cer- 
  

   tainly 
  belonging 
  to 
  the 
  great 
  group 
  of 
  the 
  Rhizopoda. 
  

  

  