﻿1032 
  Forty- 
  seventh 
  Report 
  on 
  the 
  State 
  Museum. 
  

  

  the 
  beak 
  and 
  continuous 
  beyond 
  the 
  anterior 
  edge 
  of 
  the 
  plate 
  

   into 
  long, 
  slender 
  and 
  upwardly 
  curving 
  crura. 
  Beneath 
  the 
  

   crura 
  arises 
  a 
  broad, 
  shallow, 
  trough-shaped 
  plate, 
  which, 
  near 
  

   the 
  apex, 
  is 
  supported 
  by 
  a 
  short 
  median 
  septum 
  resting 
  on 
  the 
  

   valve. 
  This 
  process 
  is 
  strongly 
  curved 
  toward 
  the 
  opposite 
  valve 
  

   and 
  is 
  continued 
  for 
  most 
  of 
  its 
  length 
  beyond 
  the 
  termination 
  

   of 
  the 
  median 
  septum. 
  Usually 
  it 
  widens 
  outwardly, 
  and 
  then 
  

   narrows 
  rather 
  abruptly, 
  or 
  even 
  acutely, 
  to 
  its 
  extremity. 
  The 
  

   adductor 
  muscular 
  scars 
  are 
  well 
  developed 
  in 
  this 
  valve, 
  forming 
  

   a 
  broadly 
  oval 
  or 
  subcircular 
  impression. 
  

  

  Vascular 
  sinuses 
  are 
  sometimes 
  retained 
  on 
  both 
  valves. 
  

  

  Type, 
  Gamarophoria 
  Schlotheimi, 
  von 
  Buch 
  (sp.) 
  (Permian). 
  

  

  Distribution. 
  Devonian 
  — 
  Permian. 
  

  

  Subgenus 
  Camarophorella, 
  Hall. 
  1893. 
  

   (Plate 
  45, 
  figs. 
  5, 
  6.) 
  

  

  Yalves 
  biconvex 
  and 
  subcircular 
  ; 
  without 
  median 
  fold, 
  sinus 
  

   and 
  plications, 
  the 
  surface 
  being 
  smooth 
  and 
  regularly 
  arched. 
  

   Internal 
  characters 
  normal 
  for 
  Camarophoria, 
  except 
  that 
  the 
  

   broad, 
  spatuliform 
  spondylium 
  rests 
  upon 
  the 
  valve 
  for 
  most 
  of 
  

   its 
  length, 
  the 
  median 
  septum 
  penetrating 
  it 
  and 
  projecting 
  above 
  

   it 
  into 
  the 
  interior 
  cavity 
  of 
  the 
  shell. 
  

  

  (Type, 
  Camarophorella 
  lenticularis, 
  White 
  and 
  "Whitfield 
  (sp.). 
  

   Burlington 
  limestone.) 
  

  

  Camarella, 
  Billings. 
  1859. 
  

   (Plate 
  45, 
  figs. 
  13-19.) 
  

  

  Valves 
  full, 
  convex, 
  smooth 
  about 
  the 
  umbonal 
  region, 
  but 
  

   anteriorly 
  developing 
  a 
  few 
  low 
  plications 
  which 
  are 
  rather 
  the 
  

   more 
  conspicuous 
  on 
  the 
  median 
  fold 
  and 
  sinus, 
  and 
  the 
  fold, 
  

   sinus 
  and 
  plications 
  are 
  clearly 
  developed 
  on 
  the 
  usually 
  abrupt 
  

   anterior 
  slope. 
  

  

  The 
  pedicle- 
  valve 
  is 
  the 
  more 
  convex 
  up 
  to 
  maturity, 
  but 
  there- 
  

   after 
  the 
  brachial 
  valve 
  becomes 
  the 
  deeper. 
  The 
  beak 
  of 
  the 
  

   pedicle- 
  valve 
  is 
  erect 
  or 
  slightly 
  incurved 
  and 
  beneath 
  it 
  lies 
  a 
  

   triangular 
  delthyrium 
  which, 
  so 
  far 
  as 
  observed, 
  shows, 
  neither 
  

   in 
  0. 
  Volborthi 
  nor 
  in 
  0. 
  Panderi, 
  any 
  evidence 
  of 
  deltidial 
  plates. 
  

   The 
  cardinal 
  slopes 
  are 
  abrupt 
  and 
  oblique, 
  and 
  no 
  cardinal 
  area 
  

   is 
  developed 
  on 
  either 
  valve. 
  On 
  the 
  interior 
  are 
  dental 
  lamellae 
  

  

  90 
  

  

  