﻿508 
  B\ 
  ALLEYNE 
  NICHOLSON 
  ON 
  SPECIES 
  OE 
  CH^TETES 
  

  

  12. 
  Chjstetes 
  mammttlattjs, 
  Edw. 
  & 
  H. 
  PL 
  XXX. 
  figs. 
  3, 
  3 
  a. 
  

   Choetetes 
  mammulatus, 
  Edwards 
  & 
  Haime, 
  Pol. 
  Eoss. 
  des 
  Terr. 
  

  

  Paleoz. 
  pi. 
  xix. 
  fig. 
  1. 
  

  

  Corallum 
  forming 
  irregular 
  expansions 
  of 
  very 
  considerable 
  size, 
  

   sometimes 
  palmate 
  or 
  lobate, 
  carrying 
  the 
  polypes 
  on 
  both 
  sides, 
  and 
  

   from 
  2 
  to 
  4 
  lines 
  in 
  thickness. 
  Surface 
  covered 
  with 
  well-marked 
  

   tuberosities, 
  the 
  prominence 
  of 
  which 
  varies 
  in 
  different 
  specimens, 
  

   but 
  which 
  are 
  covered 
  with 
  calices 
  slightly 
  larger 
  than 
  the 
  average, 
  

   occasionally 
  with 
  a 
  few 
  intercalated 
  tubes 
  of 
  minute 
  size. 
  The 
  

   tubercles 
  are 
  somewhat 
  irregularly 
  arranged 
  in 
  diagonal 
  lines, 
  and 
  

   are 
  placed 
  at 
  intervals 
  of 
  from 
  half 
  a 
  line 
  to 
  more 
  than 
  one 
  line 
  

   apart. 
  The 
  corallites 
  are 
  subequal, 
  polygonal, 
  with 
  thiu 
  walls, 
  from 
  

   eight 
  to 
  ten 
  in 
  the 
  space 
  of 
  one 
  line. 
  Very 
  rarely, 
  and 
  quite 
  as 
  an 
  

   exceptional 
  thing, 
  one 
  or 
  two 
  very 
  minute 
  tubules 
  may 
  be 
  inter- 
  

   calated 
  at 
  the 
  angles 
  of 
  the 
  larger 
  corallites. 
  

  

  This 
  species 
  represents 
  0. 
  Dalei 
  in 
  the 
  ramose 
  group, 
  but 
  is 
  di- 
  

   stinguished 
  by 
  its 
  much 
  less 
  prominent 
  tubercles 
  and 
  its 
  mode 
  of 
  

   growth. 
  It 
  is 
  further 
  distinguished 
  by 
  the 
  small, 
  thin-walled, 
  poly- 
  

   gonal 
  corallites, 
  the 
  absence 
  of 
  exceedingly 
  minute 
  intermediate 
  

   tubuli, 
  and 
  the 
  fact 
  that 
  the 
  surface-tubercles 
  are 
  covered 
  with 
  

   calices 
  which 
  in 
  general 
  are 
  rather 
  above 
  the 
  average 
  size. 
  Our 
  

   numerous 
  specimens 
  are 
  all 
  broad 
  undulating 
  expansions 
  of 
  com- 
  

   paratively 
  small 
  thickness, 
  and 
  thus 
  depart 
  somewhat 
  from 
  the 
  

   typical 
  form 
  of 
  the 
  species. 
  

  

  Locality 
  and 
  Formation. 
  Common 
  in 
  the 
  Cincinnati 
  group, 
  near 
  

   Cincinnati, 
  Ohio. 
  Collected 
  by 
  Prof. 
  Edward 
  Orton 
  and 
  Mr. 
  U. 
  P. 
  

   James. 
  

  

  13. 
  Choetetes 
  erondost/s, 
  D'Orb. 
  (?). 
  PL 
  XXX. 
  figs. 
  2-2 
  b. 
  

  

  Chcetetes 
  frondosus, 
  Edwards 
  & 
  Haime, 
  Pol. 
  Eoss. 
  des 
  Terr. 
  

   Paleoz. 
  pi. 
  xix. 
  fig. 
  5. 
  

  

  I 
  am 
  not 
  at 
  all 
  satisfied 
  that 
  the 
  specimens 
  which 
  have 
  been 
  

   placed 
  in 
  my 
  hands 
  with 
  this 
  name 
  are 
  really 
  identical 
  with 
  

   D'Orbigny's 
  species, 
  from 
  which 
  they 
  seem 
  to 
  differ 
  in 
  some 
  im- 
  

   portant 
  points. 
  I 
  am, 
  however, 
  unable 
  at 
  this 
  moment 
  to 
  refer 
  to 
  

   D'Orbigny's 
  description 
  of 
  the 
  species, 
  and 
  I 
  shall 
  therefore 
  

   describe 
  our 
  examples 
  provisionally 
  under 
  the 
  above 
  title. 
  If 
  they 
  

   should 
  prove 
  to 
  be 
  new, 
  the 
  name 
  of 
  Chastetes 
  ohioensis 
  might 
  be 
  

   applied 
  to 
  them. 
  The 
  characters 
  exhibited 
  by 
  our 
  specimens 
  are 
  as 
  

   follows 
  : 
  — 
  Corallum 
  forming 
  erect, 
  flattened, 
  undulating 
  expansions, 
  

   polypiferous 
  on 
  both 
  sides, 
  of 
  unknown 
  but 
  considerable 
  height, 
  and 
  

   varying 
  from 
  less 
  than 
  1 
  line 
  to 
  3 
  lines 
  in 
  thickness. 
  Calices 
  

   oval 
  or 
  subcircular, 
  from 
  eight 
  to 
  ten 
  in 
  the 
  space 
  of 
  one 
  line, 
  

   almost 
  half 
  their 
  own 
  diameter 
  apart, 
  separated 
  by 
  a 
  great 
  number 
  

   of 
  exceedingly 
  minute 
  tubuli, 
  which 
  render 
  the 
  spaces 
  between 
  the 
  

   average 
  corallites 
  minutely 
  porous. 
  Surface 
  with 
  stellate 
  spaces, 
  

   which 
  are 
  sometimes 
  slightly 
  elevated 
  above 
  the 
  surface 
  as 
  very 
  

   low, 
  rounded 
  tubercles, 
  but 
  which 
  are 
  more 
  commonly 
  level 
  with 
  

   the 
  general 
  surface, 
  and 
  which, 
  instead 
  of 
  bearing 
  average 
  or 
  large- 
  

  

  