﻿154 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  late, 
  and 
  are 
  made 
  up 
  of 
  long, 
  strongly 
  cuneiform 
  joints. 
  Stem 
  

   consisting 
  of 
  circular 
  joints 
  pierced 
  by 
  a 
  circular 
  axial 
  canal. 
  

  

  Stephanocrinus 
  angulatus 
  Conrad 
  (Fig. 
  48) 
  (Hall. 
  1852. 
  Pal. 
  

   N. 
  Y. 
  2:212, 
  pi. 
  48, 
  83) 
  

  

  Distinguishing 
  characters. 
  Thick, 
  equal 
  stem 
  joints, 
  with 
  crenu- 
  

   lated, 
  articulating 
  margins, 
  and 
  minute 
  round 
  canal; 
  form 
  of 
  calyx 
  

  

  k 
  A 
  A 
  

  

  ..^1D 
  

  

  t:;M! 
  

  

  /■' 
  

  

  

  w., 
  

  

  

  \' 
  

  

  Fig. 
  48 
  Stephanocrinus 
  angulatus 
  with 
  an 
  enlargement 
  of 
  the 
  stem 
  and 
  an 
  analysis 
  of 
  the 
  calyx 
  

  

  reverse 
  pyramidal, 
  gradually 
  spreading 
  from 
  a 
  triangular 
  base 
  up- 
  

   ward; 
  sutures 
  scarcely 
  visible; 
  three 
  basals, 
  one 
  pentagonal 
  and 
  two 
  

   heptagonal; 
  radials 
  hexagonal 
  with 
  short 
  excavated 
  upper 
  side; 
  in- 
  

   terradials 
  broad 
  below, 
  contracting 
  upward 
  to 
  form 
  the 
  coronal 
  

   points; 
  strong 
  and 
  angular 
  carinae, 
  six 
  of 
  which 
  alternately 
  con- 
  

   verge 
  upward 
  and 
  downward, 
  while 
  two 
  others, 
  somewhat 
  stronger, 
  

   extend 
  from 
  the 
  bases 
  of 
  the 
  heptagonal 
  basals 
  to 
  the 
  summit 
  of 
  the 
  

   radials 
  immediately 
  succeeding; 
  elevated 
  tuberculated 
  striae 
  of 
  the 
  

   plates 
  which 
  extend 
  transversely, 
  vertically 
  or 
  obliquely 
  on 
  different 
  

   parts 
  of 
  the 
  calyx; 
  surface 
  sometimics 
  merely 
  tuberculated. 
  

  

  Found 
  in 
  certain 
  thin 
  calcareous 
  layers 
  of 
  the 
  lower 
  Rochester 
  

   shale 
  at 
  Niagara, 
  sometimes 
  quite 
  abundantly. 
  Also 
  in 
  the 
  same 
  

   shale 
  at 
  Lockport 
  (Hall). 
  The 
  crinoid 
  is 
  generally 
  much 
  lighter 
  in 
  

   color 
  than 
  the 
  inclosing 
  rock, 
  and 
  is 
  easily 
  distinguished. 
  Associated 
  

  

  