﻿3i8 
  O. 
  W. 
  SKRT7BS0LE 
  ON 
  A. 
  NEW 
  SPECIES 
  OF 
  

  

  Phyllopora 
  multipora, 
  sp. 
  nov. 
  

  

  Spec. 
  char. 
  Zoariuni 
  an 
  open 
  network 
  of 
  anastomosing 
  branches 
  : 
  

   base 
  solid, 
  forming 
  an 
  infunclibuliform 
  or 
  folded 
  expansion 
  ; 
  branches 
  

   regular, 
  flattened, 
  dichotomous, 
  anastomosing 
  ; 
  on 
  poriferous 
  face 
  a 
  

   wavy 
  ridge 
  between 
  the 
  longitudinal 
  lines 
  of 
  cells 
  ; 
  reverse 
  face 
  

   smooth 
  ; 
  fenestras 
  ovate, 
  with 
  pointed 
  ends, 
  1| 
  line 
  in 
  length 
  ; 
  

   zocecia 
  immersed, 
  small, 
  prominent, 
  and 
  projected 
  when 
  not 
  worn 
  

   down, 
  twice 
  their 
  diameter 
  apart, 
  arranged 
  in 
  longitudinal 
  lines 
  

   having 
  an 
  oblique 
  direction. 
  Six 
  or 
  seven 
  cells 
  in 
  one 
  line 
  longitu- 
  

   dinally, 
  and 
  four 
  or 
  five 
  in 
  one 
  line 
  transversely. 
  

  

  Loc. 
  In 
  a 
  Permian 
  Limestone 
  quarry, 
  Hylton 
  Castle, 
  near 
  Sun- 
  

   derland. 
  

  

  •Obs. 
  The 
  present 
  species 
  may 
  be 
  readily 
  distinguished 
  from 
  the 
  

   other 
  Permian 
  Polyzoa 
  by 
  the 
  minuteness 
  of 
  its 
  cells. 
  Hence, 
  in 
  a 
  

   given 
  space, 
  Phyllopora 
  multipora 
  will 
  bo 
  found 
  by 
  comparison 
  with 
  

   all 
  other 
  species 
  to 
  have 
  double 
  the 
  number 
  of 
  cells. 
  Prom 
  allied 
  

   forms 
  it 
  may 
  be 
  known 
  by 
  the 
  ovato 
  fenestra*. 
  

  

  There 
  are 
  probably 
  two 
  distinct 
  species, 
  or 
  types 
  of 
  species, 
  of 
  

   Phyllopora, 
  ranging 
  from 
  the 
  Lower 
  Silurian 
  to 
  the 
  Permian 
  era. 
  

   The 
  type 
  of 
  each 
  species 
  is 
  most 
  distinct 
  and 
  persistent. 
  The 
  

   zoarium 
  of 
  the 
  one 
  maj* 
  best 
  be 
  described 
  as 
  solid 
  and 
  massive, 
  

   having 
  circular 
  apertures 
  or 
  fenestras, 
  in 
  which 
  the 
  branch 
  is 
  lost 
  

   in 
  the 
  solidity 
  of 
  the 
  zoarium. 
  In 
  the 
  other 
  type 
  the 
  zoarium 
  is 
  

   a 
  network 
  in 
  which 
  tho 
  branch 
  is 
  seen 
  to 
  interlace 
  and 
  coalesce, 
  

   giving 
  rise 
  to 
  fenestras 
  either 
  square, 
  ovate, 
  or 
  lozenge-shaped, 
  

   more 
  frequently 
  the 
  latter. 
  In 
  both 
  types 
  there 
  is 
  an 
  absence 
  of 
  

   dissepiments, 
  and 
  the 
  whole 
  of 
  the 
  poriferous 
  face 
  is 
  crowded 
  with 
  

   the 
  characteristic 
  small 
  cell- 
  apertures. 
  

  

  Notwithstanding 
  the 
  little 
  work 
  that 
  has 
  been 
  done 
  in 
  connexion 
  

   with 
  Phyllopora, 
  there 
  is 
  yet 
  evidence 
  forthcoming 
  of 
  the 
  existence 
  

   of 
  the 
  types 
  I 
  have 
  mentioned. 
  In 
  the 
  Lower 
  Silurian 
  rocks 
  PhyU 
  

   lopora 
  is 
  most 
  abundant, 
  There 
  are 
  at 
  least 
  two 
  distinct 
  species, 
  

   if 
  not 
  more. 
  The 
  preservation 
  of 
  the 
  remains 
  in 
  these 
  beds 
  is 
  most 
  

   unfavourable 
  for 
  exact 
  work, 
  occurring, 
  as 
  they 
  often 
  do, 
  in 
  coarse 
  

   ash 
  or 
  shale 
  and 
  distorted 
  by 
  cleavage. 
  

  

  Prom 
  the 
  Devonian 
  rocks 
  Phillips 
  figures 
  the 
  Phyllopora 
  with 
  cir- 
  

   cular 
  fenestras 
  as 
  Retepora 
  prisca*, 
  that 
  with 
  lozenge-shaped 
  fenestras 
  

   as 
  Fenestella 
  arthritica 
  t, 
  and 
  that 
  with 
  square 
  fenestras 
  as 
  Gorgonia 
  

   ripisteria 
  J. 
  As 
  might 
  be 
  expected, 
  there 
  is 
  considerable 
  confusion 
  of 
  

   species 
  in 
  Phillips's 
  delineation 
  of 
  the 
  Devonian 
  Polyzoa. 
  Two 
  or 
  

   more 
  varieties 
  are 
  included 
  under 
  one 
  head. 
  A 
  revision 
  of 
  the 
  

   Devonian 
  Polyzoa 
  from 
  a 
  palasontological 
  point 
  of 
  view 
  is 
  very 
  

   desirable, 
  for 
  since 
  Phillips's 
  work, 
  forty 
  years 
  ago, 
  they 
  have 
  re- 
  

   mained 
  untouched. 
  The 
  difficulty 
  is 
  to 
  procure 
  the 
  material 
  neces- 
  

   sary 
  for 
  the 
  purpose. 
  

  

  In 
  the 
  Carboniferous 
  rocks 
  Phyllopora 
  is 
  comparatively 
  rare 
  m 
  

  

  * 
  Phillips, 
  Pal. 
  Foss. 
  pi. 
  xiii. 
  fig. 
  c, 
  

   f 
  Ibid. 
  pi. 
  xii. 
  fig. 
  e. 
  

   + 
  Ibid. 
  pi. 
  ad- 
  fig. 
  b< 
  

  

  