﻿<&. 
  E. 
  VINE 
  ON 
  THE 
  WEDLOCK 
  POLTZOA. 
  53 
  

  

  " 
  Colony 
  composed 
  of 
  ovoid 
  or 
  pyriform 
  calcareous 
  vesicles, 
  

   varying 
  in 
  length 
  from 
  one 
  fifth 
  to 
  one 
  third 
  of 
  a 
  line, 
  and 
  usually 
  

   disposed 
  in 
  stellate 
  clusters, 
  each 
  containing 
  from 
  three 
  to 
  six 
  cells, 
  

   or 
  sometimes 
  more 
  " 
  *. 
  In 
  the 
  Devonian 
  species 
  the 
  cells 
  are 
  dis- 
  

   tinctly 
  f 
  oraminated 
  in 
  lines, 
  a 
  feature 
  that 
  I 
  have 
  not 
  detected 
  in 
  the 
  

   Silurian 
  specimens. 
  In 
  other 
  respects, 
  in 
  the 
  arrangement 
  of 
  the 
  

   stellate 
  clusters, 
  the 
  partially 
  isolated 
  vesicles, 
  and 
  the 
  connexion 
  

   of 
  these 
  by 
  stolon-like 
  processes, 
  the 
  species 
  and 
  the 
  variety 
  are 
  

   very 
  similar. 
  The 
  vesicles 
  in 
  the 
  Silurian 
  variety 
  vary 
  from 
  about 
  

   one 
  sixth 
  to 
  one 
  fifth 
  of 
  a 
  line 
  in 
  length. 
  

  

  Obs. 
  Accepting 
  freely 
  the 
  full 
  description 
  of 
  the 
  species 
  as 
  given 
  

   by 
  Messrs. 
  Nicholson 
  and 
  Etheridge, 
  jun., 
  I 
  have 
  thought 
  that 
  it 
  

   would 
  be 
  best 
  to 
  give 
  only 
  those 
  characters 
  that 
  are 
  found 
  in 
  

   my 
  Silurian 
  specimens. 
  I 
  thus 
  avoid 
  making 
  a 
  new 
  species 
  ; 
  but 
  

   by 
  distinguishing 
  it 
  by 
  a 
  varietal 
  name 
  prominence 
  is 
  given 
  to 
  an 
  

   earlier 
  type. 
  

  

  Habitat. 
  On 
  stems 
  of 
  crinoids 
  and 
  broken 
  shells. 
  

  

  Localities. 
  Buildwas 
  beds. 
  Rather 
  frequent 
  in 
  those 
  marked 
  

   36 
  and 
  38, 
  somewhat 
  rare 
  in 
  the 
  other 
  washings. 
  

  

  Fig. 
  3. 
  — 
  Ascodictyon 
  radiciforme, 
  Vine. 
  

   3 
  

  

  The 
  general 
  habit 
  of 
  the 
  clustering 
  filaments 
  round 
  a 
  central 
  axis 
  : 
  X 
  24. 
  The 
  

   specimen 
  selected 
  for 
  illustration 
  is 
  typical 
  of 
  the 
  whole 
  group 
  ; 
  but 
  there 
  

   are 
  many 
  varieties 
  of 
  stellate 
  clusters. 
  

  

  5. 
  Ascodictyon 
  eadicifoeme, 
  sp. 
  n. 
  (Fig. 
  3.) 
  

  

  Sp. 
  Char. 
  Colony 
  composed 
  of 
  elongated 
  root-like 
  processes, 
  which 
  

   vary 
  in 
  length 
  from 
  three 
  quarters 
  of 
  a 
  line 
  to 
  a 
  line. 
  These 
  pro- 
  

   cesses 
  are 
  sometimes 
  jointed; 
  and 
  they 
  are 
  disposed 
  in 
  circles, 
  un- 
  

   evenly 
  developed, 
  radiating 
  round 
  a 
  common 
  axis, 
  which 
  may 
  be 
  

  

  * 
  Nich. 
  op. 
  cit. 
  p. 
  464. 
  

  

  