﻿l82 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  PLATE 
  6 
  

  

  i 
  Caryocrinites 
  ornatus 
  Say, 
  a 
  cystid 
  having 
  a 
  

   small 
  gastropod 
  (Strophostylus) 
  attached 
  and 
  covering 
  

   the. 
  apertures 
  of 
  the 
  summit. 
  From 
  the 
  Upper 
  Siluric 
  

   (Rochester) 
  shale 
  of 
  western 
  New 
  York 
  

  

  2 
  Glyptocrinus 
  (decadactylus 
  Hall) 
  with 
  a 
  

   holostomatous 
  gastropod, 
  Cyclonema 
  bilix, 
  in- 
  

   closed 
  wi;hin 
  the 
  arms 
  in 
  an 
  attitude 
  of 
  feeding 
  at 
  or 
  

   near 
  the 
  anal 
  aperture 
  of 
  the 
  crinoid. 
  From 
  the 
  Cincinnati 
  

   shale 
  

   3,4 
  Cromyocrinus 
  simplex 
  with 
  attached 
  Platyceras 
  

   of 
  relatively 
  large 
  size, 
  its 
  anterior 
  portion 
  covering 
  the 
  

   anal 
  aperture 
  of 
  the 
  crinoid 
  while 
  the 
  rest 
  of 
  the 
  lip 
  

   of 
  the 
  snail 
  extends 
  over 
  the 
  entire 
  hight 
  of 
  the 
  calyx. 
  

   Carbonic 
  limestone, 
  Moscow, 
  Russia 
  

  

  5 
  Platyceras 
  enveloping 
  the 
  dome 
  of 
  Arthracantha 
  

  

  punctobrachiata 
  Williams 
  [after 
  Hinde, 
  Ann 
  &. 
  

   Mag. 
  Nat. 
  Hist. 
  1885]. 
  From 
  the 
  Hamilton 
  group 
  

  

  6 
  A 
  part 
  of 
  the 
  tegmen 
  ofStrotocrinus 
  regalis 
  Hall 
  

  

  showing 
  the 
  successive 
  growth 
  marks 
  made 
  by 
  an 
  attached 
  

   Platyceras, 
  always 
  keeping 
  its 
  anterior 
  extremity 
  over 
  

   the 
  anal 
  aperture 
  of 
  the 
  crinoid 
  [after 
  Keyes, 
  Acad. 
  Nat. 
  

   Sci. 
  Phila. 
  Proc. 
  1890. 
  pi. 
  2, 
  fig. 
  7]. 
  From 
  the 
  Carbonic 
  

   (Mississippian) 
  of 
  Crawfordsville, 
  Ind. 
  

  

  7 
  Platyceras 
  infundibulum 
  Meek 
  & 
  Worthen 
  

  

  attached 
  to 
  the 
  anal 
  surface 
  ofPlatycrinus 
  hemi- 
  

   sphericusM. 
  &W. 
  [after 
  Keyes 
  ut. 
  cit. 
  fig. 
  10] 
  

  

  8 
  Actinocrinus 
  multiramosus 
  Wachsmuth 
  & 
  Springer. 
  

  

  The 
  calyx 
  with 
  a 
  starfish 
  (Onychaster) 
  fastened 
  to 
  the 
  

   anal 
  tube 
  [after 
  Wachmuth 
  & 
  Springer 
  ut 
  cit. 
  pi. 
  55, 
  fig. 
  3] 
  

  

  