﻿208 
  Twenty-eighth 
  Eeport 
  ox 
  the 
  State 
  Museum. 
  

  

  numerous 
  unequal 
  internal 
  chambers 
  with 
  correspondingly 
  

   numerous 
  ambulacra, 
  are 
  distinctive. 
  

  

  The 
  external 
  aspect 
  of 
  the 
  specimens 
  is 
  similar 
  to 
  that 
  of 
  a 
  

   Favosite 
  or 
  Sponge 
  ; 
  and 
  it 
  is 
  is 
  only 
  under 
  favorable 
  condi- 
  

   tions 
  of 
  weathering 
  that 
  the 
  true 
  stellate 
  structure 
  of 
  the 
  ex- 
  

   ternal 
  walls 
  is 
  exhibited. 
  

  

  Formation 
  and 
  locality. 
  In 
  the 
  Tentaculite 
  limestone 
  of 
  

   the 
  Lower 
  Helderberg 
  group, 
  at 
  Schoharie, 
  N. 
  Y. 
  

  

  Camaeoceixus 
  Saffoedi 
  n. 
  sp. 
  

  

  ^ 
  Plate 
  36, 
  figs. 
  1—6 
  ; 
  Plate 
  37, 
  figs. 
  1, 
  2. 
  

  

  Body 
  spherical 
  to 
  oblate-spheroidal, 
  vertically 
  or 
  trans- 
  

   versely 
  compressed 
  and 
  externally 
  lobed; 
  presenting 
  from 
  

   three 
  to 
  five 
  large 
  lobes, 
  corresponding 
  to 
  the 
  internal 
  cham- 
  

   bers. 
  There 
  are 
  usually 
  five 
  lobes, 
  but 
  often 
  very 
  unequally 
  

   developed, 
  giving 
  an 
  unsymmetrical 
  form 
  to 
  the 
  bod} 
  r 
  . 
  

  

  Basal 
  area 
  small, 
  well 
  defined 
  ; 
  limited 
  by 
  an 
  extension 
  of 
  

   the 
  wal]s, 
  and 
  occupying 
  a 
  space 
  having 
  a 
  diameter 
  of 
  about 
  

   one-third 
  the 
  transverse 
  diameter 
  of 
  the 
  dome. 
  Basal 
  rays 
  

   strong, 
  their 
  subdivisions 
  enclosing 
  five 
  distinct 
  ambulacral 
  

   openings 
  into 
  the 
  internal 
  chambers, 
  and 
  laterally 
  connected 
  

   by 
  numerous 
  small 
  polygonal 
  plates 
  similar 
  to 
  those 
  compos- 
  

   ing 
  the 
  walls 
  of 
  the 
  body. 
  

  

  The 
  dome 
  is 
  ordinarily 
  divided, 
  by 
  vertical 
  partitions, 
  into 
  

   five 
  large 
  unequal 
  chambers, 
  which 
  are 
  rarely 
  of 
  a 
  uniform 
  

   size, 
  and 
  often 
  show 
  great 
  inequality. 
  In 
  some 
  specimens 
  

   one 
  or 
  more 
  of 
  the 
  chambers 
  are 
  partially 
  or 
  completely 
  atro- 
  

   phied 
  from 
  the 
  enormous 
  development 
  of 
  adjacent 
  chambers, 
  

   producing 
  forms 
  similar 
  to 
  fig. 
  3, 
  pi. 
  36, 
  and 
  figs. 
  1, 
  2, 
  pi. 
  37. 
  

  

  Internal 
  and 
  external 
  walls 
  of 
  the 
  dome 
  composed 
  of 
  small 
  

   polygonal 
  plates, 
  united 
  by 
  minutely 
  undulating 
  or 
  serrated 
  

   suture-lines. 
  The 
  external 
  plates 
  are 
  well 
  defined 
  by 
  the 
  

   depressed 
  suture-lines 
  and 
  often 
  show 
  a 
  small 
  node 
  or 
  cen- 
  

   tral 
  tubercle. 
  As 
  in 
  the 
  other 
  forms 
  here 
  described, 
  the 
  walls 
  

   readily 
  separate 
  into 
  an 
  inner 
  and 
  outer 
  layer, 
  and 
  the 
  inter- 
  

   spaces 
  have 
  a 
  porous 
  or 
  spongy 
  structure. 
  

  

  The 
  specimens 
  present 
  such 
  a 
  great 
  range 
  in 
  size 
  and 
  form 
  

   that 
  the 
  dimensions 
  are 
  not 
  apparently 
  of 
  specific 
  importance. 
  

   The 
  largest 
  example 
  observed, 
  which 
  is 
  represented 
  in 
  section 
  

   in 
  fig. 
  2, 
  pi. 
  37, 
  has 
  a 
  greatest 
  transverse 
  diameter 
  of 
  about 
  145 
  

   mm. 
  and 
  shows 
  five 
  unequal 
  internal 
  chambers. 
  The 
  trans- 
  

   verse 
  diameters 
  of 
  specimens 
  of 
  ordinary 
  size 
  vary 
  from 
  80 
  to 
  

   to 
  110 
  mm. 
  

  

  