﻿570 
  MB. 
  E. 
  A. 
  WAIEORD 
  OX 
  SOilE 
  BBTOZOA 
  FROM 
  IBE 
  

  

  leech-like 
  swellings 
  between 
  or 
  enveloping 
  six 
  or 
  eight 
  of 
  the 
  front 
  

   cells, 
  punctulate, 
  the 
  pores 
  finer 
  than 
  on 
  the 
  zoarial 
  surface. 
  There 
  

   are 
  calcareous 
  floors 
  or 
  closures 
  with 
  a 
  central 
  perforation 
  at 
  about 
  

   the 
  point 
  where 
  the 
  free 
  part 
  of 
  the 
  cell 
  commences. 
  

  

  A 
  semi-adherent 
  form 
  varies 
  but 
  little 
  in 
  zocecial 
  arrangement, 
  

   but 
  has 
  a 
  sharply 
  triangular 
  outline 
  where 
  attached. 
  One 
  fragment 
  

   only 
  of 
  a 
  numerous 
  series 
  of 
  Idmonecz 
  from 
  Eanville 
  in 
  my 
  collection 
  

   has 
  an 
  approximate 
  clavate 
  form. 
  

  

  An 
  abnormal 
  form 
  of 
  this 
  species 
  (PI. 
  XIX. 
  fig. 
  2) 
  shows 
  the 
  

   mesial 
  zocecia 
  much 
  more 
  produced 
  and 
  becoming 
  prominently 
  conical 
  

   towards 
  the 
  aperture. 
  The 
  zoarium 
  is 
  more 
  globosely 
  claviform, 
  and 
  

   has 
  new 
  colonies 
  or 
  branches 
  starting 
  from 
  the 
  non-poriferous 
  area. 
  

  

  The 
  whole 
  of 
  the 
  Idmonea-triquetra 
  series 
  from 
  the 
  Inferior 
  

   Oolite 
  of 
  Dorsetshire, 
  when 
  compared 
  with 
  the 
  allied 
  forms 
  from 
  the 
  

   Forest 
  Marble 
  (" 
  Calcaire 
  a 
  Polypiers") 
  of 
  Eanville, 
  show 
  a 
  greater 
  

   degree 
  of 
  robustness. 
  The 
  similarity 
  of 
  the 
  variations 
  of 
  growth 
  

   on 
  each 
  horizon 
  impresses 
  upon 
  the 
  observer 
  belief 
  in 
  their 
  belonging 
  

   to 
  one 
  type 
  The 
  typical 
  I. 
  triquetra, 
  Lamx.. 
  is 
  adherent 
  and 
  

   broadly 
  triangular, 
  with 
  numerous 
  rows 
  of 
  apertures 
  on 
  each 
  of 
  the 
  

   upper 
  sides. 
  In 
  the 
  Dorsetshire 
  series 
  a 
  modified 
  form 
  of 
  the 
  type 
  

   occurs. 
  In 
  the 
  several 
  Dorset 
  varieties 
  the 
  exsert 
  parts 
  of 
  the 
  

   zocecia 
  are 
  more 
  prominent, 
  especially 
  the 
  mesial 
  ones, 
  which 
  are 
  

   mammiform, 
  and 
  the 
  ridge-like 
  front 
  more 
  protuberant 
  than 
  in 
  the 
  

   Eanville 
  form. 
  

  

  Bisedmoxea. 
  

  

  Bmdmonea. 
  d'Orbi^nv. 
  Paleont. 
  Franc. 
  Terr. 
  Cret. 
  t. 
  v. 
  p. 
  720 
  

   (1852). 
  

  

  D'Orbigny 
  characterizes 
  this 
  genus 
  as 
  having 
  quadrangular 
  stems 
  

   and 
  branches, 
  with 
  alternating 
  lines 
  of 
  cells 
  upon 
  the 
  face 
  of 
  each 
  

   of 
  the 
  four 
  angles. 
  Apertures 
  prominent, 
  placed 
  one 
  above 
  the 
  

   other 
  in 
  transverse 
  lines. 
  He 
  adds 
  that 
  it 
  resembles 
  a 
  double 
  

   Idmonea. 
  One 
  finds, 
  however, 
  that 
  the 
  quadrangular 
  stems 
  merge 
  

   into 
  ovals 
  with 
  less 
  interrupted 
  lines 
  of 
  zocecia, 
  and 
  on 
  this 
  ground 
  

   as 
  well 
  as 
  its 
  mode 
  of 
  reproduction 
  the 
  species 
  is 
  removed 
  from 
  

   Entalojpliora. 
  

  

  Tine, 
  in 
  his 
  remarks 
  upon 
  E. 
  tetragona*, 
  says: 
  — 
  "I 
  am 
  not 
  sur- 
  

   prised 
  that 
  d*Orbigny 
  should 
  suggest 
  a 
  new 
  generic 
  term. 
  Bisidmonea, 
  

   for 
  this 
  species, 
  as 
  in 
  some 
  of 
  the 
  finer 
  branches 
  the 
  name 
  appears 
  

   to 
  me 
  to 
  be 
  eminently 
  suitable." 
  Waters, 
  when 
  describing 
  Idmonea 
  

   bifronsf, 
  in 
  which 
  the 
  annulations 
  of 
  zocecia 
  are 
  interrupted 
  by 
  two 
  

   mesial 
  lines, 
  speaks 
  of 
  it 
  as 
  looking 
  like 
  a 
  connecting-link 
  between 
  

   the 
  Spiropora 
  form 
  of 
  Eatcdojjliora 
  and 
  typical 
  Idmonea:. 
  

  

  * 
  Tine. 
  G. 
  E., 
  "Xotes 
  on 
  the 
  Polyzoa 
  of 
  Caen 
  and 
  Eanville 
  &c," 
  Journ. 
  

   Northampton. 
  Nat. 
  Hist. 
  Soc. 
  vol. 
  v. 
  p. 
  10 
  (1868 
  . 
  

  

  + 
  Waters, 
  A. 
  W.. 
  "On 
  Fossil 
  Cvclostoinatous 
  Bryozoa 
  from 
  Australia." 
  

   Quart. 
  Journ. 
  Geol. 
  Soe. 
  vol. 
  xl. 
  p. 
  685. 
  

  

  