﻿The 
  Fauna 
  of 
  the 
  Niagara 
  Group. 
  143 
  

  

  plates 
  quadrangular, 
  wider 
  than 
  high; 
  third 
  radials 
  penta- 
  

   gonal, 
  wider 
  than 
  high, 
  and 
  with 
  the 
  large 
  ten-sided 
  inter- 
  

   radial 
  plate, 
  giving 
  great 
  expansion 
  to 
  the 
  upper 
  part 
  of 
  the 
  

   calyx. 
  Arm 
  plates 
  narrow 
  in 
  the 
  lower 
  part, 
  but 
  becoming 
  

   gradually 
  wider 
  above, 
  giving 
  an 
  elongate 
  elliptical 
  area 
  be- 
  

   tween 
  the 
  solid 
  interbrachial 
  plates. 
  Summit 
  flat, 
  depressed, 
  

   convex 
  or 
  slightly 
  concave. 
  

  

  Column 
  round, 
  and 
  near 
  the 
  summit 
  composed 
  of 
  strong 
  

   thick 
  plates, 
  with 
  the 
  margins 
  projecting 
  and 
  rounded. 
  Sur- 
  . 
  

   face 
  ornamentation 
  always 
  conspicuous 
  and 
  characteristic 
  

   though 
  subject 
  to 
  considerable 
  variation. 
  The 
  plates 
  of 
  the 
  

   body 
  are 
  covered 
  with 
  round, 
  angular, 
  or 
  elongated 
  nodes, 
  

   and 
  sometimes 
  with 
  straight 
  or 
  tortuous 
  ridges 
  often 
  arranged 
  

   in 
  lines 
  somewhat 
  parallel 
  to 
  the 
  margins 
  of 
  the 
  plates. 
  The 
  

   younger 
  specimens 
  are 
  much 
  more 
  strongly 
  nodose 
  than 
  the 
  

   older. 
  The 
  arms 
  are 
  usually 
  marked 
  by 
  two 
  parallel 
  ranges 
  

   of 
  rounded 
  nodes 
  along 
  the 
  central 
  part, 
  while 
  there 
  is 
  a 
  range 
  

   of 
  smaller 
  nodes 
  on 
  the 
  exterior 
  margins. 
  These 
  nodes 
  are 
  

   sometimes 
  confluent, 
  and 
  appear 
  as 
  transverse 
  ridges. 
  The 
  

   interbrachial 
  plates 
  are 
  marked 
  by 
  two 
  ranges 
  of 
  rounded 
  or 
  

   transversely 
  elongated 
  nodes. 
  

  

  Figures 
  4 
  and 
  8 
  of 
  plate 
  16 
  exhibit 
  the 
  base 
  and 
  upper 
  mar- 
  

   gins 
  of 
  a 
  large 
  individual. 
  The 
  largest 
  specimen 
  of 
  the 
  calyx 
  

   observed 
  has 
  a 
  diameter 
  of 
  50 
  mm. 
  with 
  a 
  height 
  of 
  25 
  mm. 
  

  

  The 
  distinguishing 
  features 
  of 
  this 
  species, 
  as 
  it 
  occurs 
  in 
  

   the 
  Waldron 
  collections, 
  are 
  the 
  general 
  rotund 
  ovoid 
  form, 
  

   broad 
  spreading 
  calyx, 
  with 
  about 
  one-third 
  the 
  height 
  of 
  

   the 
  first 
  radials 
  covered 
  by 
  the 
  column 
  ; 
  the 
  arms 
  stout 
  and 
  

   each 
  pair 
  in 
  length 
  about 
  three 
  to 
  three 
  and, 
  a 
  half 
  times 
  their 
  

   greatest 
  width. 
  

  

  For 
  diagram 
  of 
  structure 
  of 
  E. 
  ccelatus 
  see 
  20th 
  ^Report 
  on 
  

   the 
  State 
  Cabinet 
  of 
  Natural 
  History, 
  page 
  321 
  ; 
  Revised 
  edi- 
  

   tion, 
  page 
  363. 
  

  

  EUCALYPTOCRINUS 
  OVALIS 
  TrOOSt. 
  

   Plate 
  17, 
  Figs. 
  12, 
  13. 
  

  

  Eucalyptocrinus 
  oralis 
  Troost. 
  Catalogue 
  of 
  Crinoidea. 
  1849. 
  

   Eucalyptocrinus 
  ovatus 
  (in 
  error 
  for 
  E. 
  ovalis). 
  Doc. 
  Edit. 
  28th 
  Rep. 
  St. 
  Mus. 
  Nat- 
  

   Hist. 
  Explanation 
  of 
  pi. 
  17, 
  figs. 
  12, 
  13. 
  1876. 
  

  

  Body 
  oval-ovoid, 
  outline 
  curved 
  from 
  base 
  to 
  summit 
  ; 
  the 
  

   calyx 
  somewhat 
  deeply 
  cup-shaped, 
  and 
  having 
  a 
  height 
  

  

  