﻿996 
  Fortt-sevei\te 
  Report 
  on 
  tee 
  State 
  Museum. 
  

  

  reaching 
  for 
  nearly 
  the 
  entire 
  length 
  of 
  the 
  valve 
  and 
  rising 
  ver- 
  

   tically, 
  beneath 
  the 
  lateral 
  jugal 
  processes, 
  almost 
  to 
  the 
  jugal 
  

   angle 
  . 
  

  

  Shell 
  substance 
  fibrous, 
  impunctate. 
  

  

  Type, 
  Anojplotheca 
  vennsta, 
  Sohnur 
  (sp.). 
  

  

  Distribution. 
  Middle 
  Devonian 
  (Eifel 
  and 
  Torquay). 
  

  

  Subgenus 
  Ccelospira, 
  Hall. 
  1863. 
  

   (Plate 
  89, 
  figs. 
  8-17.) 
  

  

  Shells 
  concavo-convex, 
  oval 
  or 
  circular, 
  with 
  coarse 
  or 
  fine 
  

   radial, 
  simple 
  or 
  compound 
  plications. 
  The 
  pedicle-valve 
  has 
  dis- 
  

   tant 
  teeth 
  arising 
  from 
  the 
  lateral 
  cardinal 
  slopes, 
  and 
  in 
  front 
  of 
  

   the 
  umbonal 
  cavity 
  are 
  a 
  pair 
  of 
  rather 
  deep 
  oval 
  diductor 
  scars, 
  

   which 
  embrace 
  the 
  anterior 
  extremities 
  of 
  two 
  narrow, 
  less 
  exca- 
  

   vated 
  adductors. 
  These 
  are 
  separated 
  by 
  a 
  narrow, 
  more 
  or 
  less 
  

   conspicuously 
  developed 
  median 
  ridge. 
  

  

  The 
  cardinal 
  process 
  has 
  the 
  same 
  structure 
  as 
  in 
  Anoplotheoa, 
  

   consisting 
  of 
  a 
  central 
  portion 
  curved 
  backward 
  to, 
  or 
  slightly 
  

   beyond 
  the 
  hinge 
  and 
  faintly 
  bilobed 
  on 
  its 
  posterior 
  extremity. 
  

   The 
  crural 
  bases 
  are 
  consolidated 
  with 
  the 
  central 
  process 
  and 
  

   are 
  continuous 
  with 
  the 
  socket 
  walls. 
  There 
  is 
  a 
  stout 
  median 
  

   ridge 
  dividing 
  the 
  muscular 
  impressions 
  and 
  supporting 
  the 
  

   cardinal 
  process. 
  

  

  The 
  crura 
  are 
  slender 
  and 
  rather 
  long, 
  slightly 
  converging 
  

   toward 
  their 
  apices, 
  forming 
  an 
  acute 
  angle 
  where 
  they 
  meet 
  

   the 
  primary 
  lamellae, 
  the 
  latter 
  turning 
  outward 
  and 
  backward 
  

   and 
  remaining 
  widely 
  separated 
  throughout 
  their 
  extent. 
  The 
  

   coil 
  is 
  lax, 
  the 
  ribbon 
  making 
  but 
  about 
  three 
  volutions, 
  and 
  the 
  

   cones, 
  though 
  very 
  slightly 
  elevated, 
  have 
  their 
  apices 
  directed 
  

   outward, 
  toward 
  the 
  lateral 
  slopes 
  of 
  the 
  pedicle-valve. 
  The 
  

   shells 
  vary 
  considerably 
  in 
  convexity 
  both 
  naturally 
  and 
  from 
  

   accidental 
  compression, 
  and 
  where 
  the 
  internal 
  cavity 
  is 
  shallow 
  

   the 
  spirals 
  may 
  appear 
  to 
  be 
  coiled 
  almost 
  in 
  a 
  plane. 
  

  

  The 
  umbonal 
  curves 
  of 
  the 
  primary 
  lamellae 
  are 
  very 
  broad 
  

   and 
  stout 
  ; 
  the 
  jugum 
  arises 
  on 
  their 
  posterior 
  limb, 
  is 
  broad 
  and 
  

   strong, 
  its 
  lateral 
  processes 
  curving 
  gently 
  forward 
  and 
  thence 
  

   upward, 
  being 
  elevated 
  and 
  acutely 
  angulated 
  at 
  the 
  apex. 
  

  

  Beyond 
  the 
  junction 
  of 
  the 
  lateral 
  processes 
  the 
  jugum 
  is 
  con- 
  

   tinued 
  as 
  a 
  simple 
  stem 
  which 
  is 
  inclined 
  backward 
  and 
  may 
  

  

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