﻿136 
  Twenty-eighth 
  Report 
  on 
  the 
  State 
  Museum. 
  

  

  Cyathocrinus 
  nucleus. 
  

  

  Plate 
  15, 
  Figs. 
  7-9. 
  

  

  Dendrocrinus 
  nucleus 
  Hall. 
  Doc. 
  Edit. 
  28th 
  Rep. 
  St. 
  Mus. 
  Nat. 
  Hist. 
  Explana- 
  

   tion 
  of 
  pi. 
  15, 
  figs. 
  7-9. 
  1876. 
  

  

  Body 
  of 
  medium 
  size, 
  depressed-turbinate, 
  width 
  one-fourth 
  

   to 
  one-third 
  greater 
  than 
  the 
  height, 
  pentalobate 
  in 
  the 
  upper 
  

   part. 
  Basal 
  plates 
  short, 
  truncated 
  below 
  by 
  the 
  large 
  col- 
  

   umn 
  ; 
  subradial 
  plates 
  wider 
  than 
  high, 
  three 
  of 
  them 
  pentag- 
  

   onal 
  and 
  two 
  heptagonal. 
  First 
  radial 
  plates 
  large, 
  gibbous 
  

   and 
  projecting 
  laterally 
  so 
  as 
  to 
  give 
  a 
  distinctly 
  pentalobate 
  

   aspect 
  to 
  the 
  fossil 
  ; 
  second 
  radials 
  much 
  smaller 
  than 
  the 
  

   first, 
  wider 
  than 
  high, 
  and 
  separated 
  by 
  a 
  small 
  intercalated 
  

   plate 
  which 
  rests 
  upon 
  the 
  short 
  sloping 
  upper 
  lateral 
  faces 
  of 
  

   the 
  first 
  radials 
  ; 
  third 
  radials 
  subpentagonal 
  and 
  supporting 
  

   an 
  arm 
  upon 
  each 
  upper 
  sloping 
  face 
  ; 
  arms 
  (in 
  part) 
  bifur- 
  

   cating 
  on 
  the 
  third 
  plate, 
  and 
  above 
  the 
  last 
  radial 
  ; 
  anal 
  plates 
  

   two. 
  Surface 
  finely 
  and 
  strongly 
  granulose. 
  

  

  The 
  specimens 
  before 
  me 
  vary 
  from 
  a 
  height 
  of 
  8 
  to 
  11.5 
  

   mm. 
  with 
  a 
  diameter 
  of 
  10 
  to 
  15 
  mm. 
  The 
  base 
  of 
  the 
  col- 
  

   umn 
  in 
  the 
  smallest 
  measures 
  3.5 
  mm. 
  and 
  of 
  the 
  largest 
  5 
  mm. 
  

   The 
  column 
  is 
  proportionally 
  very 
  large 
  and 
  firmly 
  inserted 
  

   at 
  the 
  base, 
  the 
  upper 
  plates 
  are 
  comparatively 
  thin, 
  and 
  below 
  

   these 
  are 
  alternations 
  of 
  thicker 
  and 
  thinner 
  plates. 
  

  

  The 
  figures 
  given 
  on 
  plate 
  15 
  are 
  from 
  a 
  young 
  specimen, 
  

   and 
  do 
  not 
  fairly 
  represent 
  the 
  species. 
  The 
  cicatrices 
  on 
  the 
  

   radial 
  plates 
  are 
  too 
  narrow, 
  and 
  incorrectly 
  represented 
  as 
  

   arm-bases. 
  The 
  species 
  is 
  not 
  a 
  Dendrocrinus, 
  but 
  a 
  true 
  

   Cyathocrinus 
  in 
  structure. 
  

  

  LECANOCRINUS 
  Hall. 
  

   Lecanocrinus 
  pusillus. 
  

  

  Plate 
  15, 
  Figs. 
  1-6. 
  

  

  Cyathocrinus 
  pusillus 
  Hall. 
  Trans. 
  Alb. 
  lust!, 
  vol. 
  iv, 
  p. 
  200. 
  Abstract 
  p. 
  6; 
  

  

  May, 
  1863. 
  

   C. 
  pusillus 
  Hall. 
  20th 
  Rep. 
  State 
  Cab. 
  Nat. 
  Hist. 
  p. 
  324; 
  Rev. 
  Edit. 
  p. 
  366. 
  

   C. 
  pusillus 
  Hall. 
  Doc. 
  Edit. 
  28th 
  Rep. 
  St. 
  Mus. 
  Nat. 
  Hist. 
  Explanation 
  of 
  pi. 
  15. 
  

  

  1876. 
  

  

  Calyx 
  small, 
  forming 
  a 
  broad 
  shallow 
  cup 
  a 
  little 
  inflated 
  

   on 
  the 
  anal 
  side. 
  Basal 
  plates 
  very 
  small, 
  covered 
  for 
  nearly 
  

  

  