﻿FROM 
  THE 
  LOWER 
  SILURIAN 
  OP 
  NORTH 
  AMERICA. 
  503 
  

  

  abundant 
  and 
  may 
  be 
  absent 
  over 
  considerable 
  spaces. 
  Surface 
  

   exhibiting 
  a 
  number 
  of 
  small, 
  somewhat 
  transversely 
  elongated 
  

   tubercles, 
  placed 
  in 
  diagonal 
  lines 
  at 
  distances 
  of 
  half 
  a 
  line 
  apart 
  

   transversely 
  and 
  two 
  thirds 
  of 
  a 
  line 
  measured 
  vertically. 
  The 
  

   tubercles 
  are 
  very 
  slightly 
  elevated 
  above 
  the 
  general 
  surface, 
  and 
  

   are 
  either 
  solid 
  at 
  their 
  summits, 
  or 
  carry 
  a 
  few 
  excessively 
  small 
  

   cylindrical 
  tubuli 
  with 
  or 
  without 
  two 
  or 
  three 
  of 
  the 
  average-sized 
  

   corallites. 
  

  

  This 
  species 
  is 
  closely 
  allied 
  to 
  0. 
  Dalei, 
  from 
  which 
  it 
  is 
  distin- 
  

   guished 
  by 
  its 
  slightly 
  smaller 
  calices, 
  by 
  the 
  fact 
  that 
  the 
  tubercles 
  

   are 
  not 
  conical 
  and 
  prominent 
  and 
  are 
  not 
  covered 
  with 
  corallites 
  of 
  

   the 
  ordinary 
  size, 
  whilst 
  the 
  very 
  minute 
  intermediate 
  tubuli 
  are 
  

   either 
  absent 
  or 
  are 
  present 
  in 
  very 
  small 
  numbers. 
  

  

  Locality 
  and 
  Formation. 
  Cincinnati 
  group, 
  near 
  Cincinnati, 
  Ohio. 
  

   Collected 
  by 
  Mr. 
  U. 
  P. 
  James. 
  

  

  4. 
  Chjetetes 
  attritus, 
  Xich. 
  PI. 
  XXIX. 
  figs. 
  4, 
  4 
  a. 
  

  

  Corallum 
  composed 
  of 
  subcylindrical 
  branches, 
  having 
  a 
  diameter 
  

   of 
  from 
  5 
  to 
  7 
  lines, 
  and 
  dividing 
  at 
  short 
  intervals. 
  Corallites 
  with 
  

   thin 
  walls, 
  polygonal, 
  from 
  eight 
  to 
  ten 
  in 
  the 
  space 
  of 
  1 
  line, 
  sub- 
  

   equal, 
  some 
  being 
  smaller 
  than 
  the 
  others, 
  but 
  not 
  excessively 
  so. 
  

   No 
  very 
  minute 
  intermediate 
  tubuli 
  interspersed 
  among 
  the 
  larger 
  

   corallites. 
  Surface 
  with 
  numerous, 
  very 
  close-set, 
  quadrangular 
  or 
  

   conical 
  solid 
  eminences 
  or 
  tubercles, 
  each 
  placed 
  at 
  the 
  junction 
  

   of 
  from 
  four 
  to 
  six 
  corallites. 
  These 
  tubercles 
  are 
  from 
  four 
  to 
  

   five 
  in 
  the 
  space 
  of 
  1 
  line, 
  and 
  are 
  apparently 
  quite 
  compact, 
  carry- 
  

   ing 
  neither 
  the 
  average 
  corallites 
  nor 
  minute 
  tubuli. 
  

  

  This 
  species 
  is 
  distinguished 
  from 
  all 
  the 
  preceding 
  by 
  its 
  thin- 
  

   walled 
  corallites, 
  the 
  absence 
  of 
  excessively 
  minute 
  tubuli 
  placed 
  

   round 
  the 
  larger 
  tubes, 
  and 
  the 
  minute, 
  crowded, 
  solid 
  tubercles 
  

   which 
  stud 
  the 
  surface. 
  At 
  first 
  sight 
  examples 
  of 
  this 
  species 
  look 
  

   as 
  if 
  they 
  had 
  been 
  more 
  or 
  less 
  weathered 
  and 
  worn 
  ; 
  but 
  a 
  closer 
  

   examination 
  does 
  not 
  bear 
  out 
  this 
  view. 
  

  

  Locality 
  and 
  Formation. 
  Cincinnati 
  group, 
  near 
  Cincinnati, 
  Ohio. 
  

   Collected 
  by 
  Mr. 
  U. 
  P. 
  James. 
  

  

  5. 
  Ch^tetes 
  pulchellus, 
  Edw. 
  & 
  H. 
  PI. 
  XXIX. 
  figs. 
  5-5 
  6. 
  

   Chcetetes 
  pulcliellus, 
  Edwards 
  & 
  Haime, 
  Pol. 
  Foss. 
  des 
  Terr. 
  Paleoz. 
  

  

  p. 
  271. 
  

  

  Monticidipora 
  pulchella, 
  Edw. 
  & 
  H. 
  Brit. 
  Eoss. 
  Corals, 
  pi. 
  62. 
  

   figs. 
  5-5 
  b. 
  

  

  Corallum 
  variable 
  in 
  form, 
  usually 
  of 
  subcylindrical 
  branches, 
  

   which 
  have 
  a 
  diameter 
  of 
  from 
  2 
  to 
  6 
  lines, 
  sometimes 
  forming 
  

   flattened 
  and 
  expanded 
  subpalmate 
  fronds, 
  sometimes 
  inosculating. 
  

   Corallites 
  thin-walled, 
  polygonal, 
  unequal 
  in 
  size, 
  about 
  eight 
  of 
  the 
  

   average 
  ones 
  occupying 
  the 
  space 
  of 
  1 
  line. 
  Surface 
  exhibiting 
  

   rounded 
  or 
  somewhat 
  stellate 
  groups 
  of 
  larger 
  corallites, 
  of 
  which 
  

   two 
  or 
  three 
  occupy 
  the 
  space 
  of 
  half 
  a 
  line, 
  and 
  which 
  sometimes 
  

   have 
  very 
  minute 
  intermediate 
  tubuli 
  between 
  them. 
  These 
  groups 
  

   of 
  larger 
  corallites 
  generally 
  comprise 
  from 
  five 
  to 
  seven 
  individuals, 
  

  

  