﻿Report 
  of 
  the 
  State 
  Geologist. 
  371 
  

  

  Amboccelia 
  spinosa, 
  sp, 
  nov. 
  

   Plate 
  IY, 
  figs. 
  6-8. 
  

  

  Shell 
  of 
  rather 
  large 
  size, 
  hinge-line 
  straight 
  equalling 
  the 
  full 
  

   diameter 
  of 
  the 
  valve. 
  Brachial 
  valve 
  depressed-convex 
  in 
  the 
  

   umbonal 
  region, 
  concave 
  anteriorly 
  with 
  upturned 
  margins. 
  

   Medially 
  there 
  is 
  a 
  low 
  and 
  indistinct 
  elevation 
  which 
  disappears 
  

   toward 
  the 
  front. 
  Pedicle-valve 
  not 
  known. 
  Surface 
  bearing 
  

   faint 
  traces 
  of 
  concentric 
  lines 
  and 
  covered 
  with 
  numerous 
  

   elongate 
  depressions 
  which 
  were 
  probably 
  bases 
  of 
  insertion 
  of 
  

   epidermal 
  spinules. 
  

  

  Length 
  of 
  the 
  original 
  specimen, 
  7 
  mm.; 
  width 
  on 
  the 
  hinge, 
  

   9 
  mm. 
  

  

  Hamilton 
  shales. 
  At 
  about 
  300 
  feet 
  in 
  the 
  Livonia 
  Shaft. 
  

  

  Hyalostelia 
  (?) 
  Marcellia, 
  sp. 
  nov. 
  

   Plate 
  IV, 
  figs. 
  19-22. 
  

  

  In 
  the 
  Marcellus 
  shales, 
  at 
  a 
  depth 
  in 
  the 
  Shaft 
  of 
  812 
  to 
  823 
  

   feet, 
  there 
  were 
  found 
  in 
  considerable 
  abundance, 
  broad, 
  thin, 
  film- 
  

   like 
  expansions 
  tinging 
  the 
  rock 
  surface, 
  from 
  pyritization, 
  a 
  

   greenish 
  or 
  yellowish 
  hue, 
  but 
  having 
  no 
  definite 
  limits, 
  making 
  

   irregular 
  splotches 
  of 
  discoloration. 
  When 
  magnified 
  these 
  

   patches 
  are 
  seen 
  to 
  be 
  composed 
  of 
  masses 
  of 
  minute 
  rod-like 
  

   and 
  often 
  cruciform 
  sponge 
  spicules, 
  changed 
  to 
  pyrite. 
  The 
  

   cruciform 
  spicules 
  are 
  evidently 
  hexactinellid 
  as 
  many 
  of 
  them 
  

   which 
  exhibit 
  but 
  four 
  branches 
  on 
  the 
  same 
  plane 
  show 
  the 
  

   bases 
  of 
  the 
  other 
  two 
  rising 
  in 
  the 
  plane 
  at 
  right 
  angles; 
  in 
  

   some, 
  however, 
  there 
  seems 
  to 
  be 
  no 
  evidence 
  of 
  more 
  than 
  four 
  

   rays. 
  With 
  these 
  spicules 
  are 
  found 
  larger 
  and 
  coarser 
  spicular 
  

   bands, 
  flat, 
  straight, 
  thickened 
  on 
  the 
  edges 
  or 
  in 
  the 
  middle, 
  

   and 
  not 
  at 
  all 
  unlike 
  small 
  blades 
  of 
  grass. 
  Thtse 
  end 
  abruptly 
  

   at 
  one 
  end 
  but 
  taper 
  to 
  the 
  other, 
  though 
  showing 
  no 
  evidence 
  

   of 
  terminating 
  in 
  an\^ 
  appliance 
  for 
  attachment. 
  

  

  There 
  is 
  no 
  evidence 
  whatever 
  that 
  these 
  broad 
  ribbon-like 
  

   spicular 
  strands 
  are 
  composed 
  of 
  separate 
  spicular 
  rods, 
  but, 
  on 
  

   the 
  contrary, 
  they 
  are 
  clearly 
  distinct 
  and 
  simple 
  bodies. 
  Their 
  

   association 
  with 
  the 
  cruciform 
  spicules 
  is 
  so 
  close 
  and 
  invariable 
  

   as 
  to 
  enforce 
  the 
  organic 
  connection 
  of 
  the 
  two; 
  and 
  yet 
  we 
  are 
  at 
  

   a 
  loss 
  to 
  interpret 
  their 
  meaning 
  as, 
  to 
  our 
  knowledge, 
  there 
  has 
  

   been 
  no 
  similar 
  structure 
  observed 
  among 
  the 
  hexactinellids. 
  

  

  