﻿Report 
  of 
  the 
  State 
  Geologist. 
  

  

  995 
  

  

  faces 
  are 
  vertical 
  and 
  their 
  upper 
  surfaces 
  small 
  and 
  sub 
  triangular. 
  

   They 
  do 
  not 
  unite 
  with 
  each 
  other 
  at 
  any 
  point, 
  but 
  each 
  is 
  

   curved 
  slightly 
  back 
  of 
  the 
  cardinal 
  line, 
  and 
  

   on 
  its 
  ante-lateral 
  angle 
  supports 
  a 
  crus. 
  The 
  

   juguni 
  is 
  situated 
  at 
  about 
  the 
  center 
  of 
  the 
  

   primary 
  lamellae, 
  bends 
  backward 
  for 
  a 
  short 
  

   distance, 
  and 
  then 
  forward 
  at 
  an 
  abrupt 
  angle. 
  

   Bevond 
  this 
  angulation 
  its 
  length 
  is 
  about 
  

  

  Fig. 
  371. 
  Jugum 
  of 
  Para- 
  

  

  twice 
  that 
  before 
  it. 
  It 
  terminates 
  as 
  in 
  zyga 
  tursuta, 
  Haii. 
  

   Tkematospika, 
  in 
  a 
  short, 
  sharp 
  and 
  simple 
  horizontal 
  process 
  

   directed 
  posteriorly. 
  

  

  Type, 
  Parazyga 
  hirsuta. 
  Hall. 
  Hamilton 
  group. 
  

  

  Distribution. 
  Devonian. 
  

  

  Anoplotheca, 
  Sandberger. 
  1855. 
  

   (Plate 
  30, 
  figs. 
  1-8.) 
  

  

  Synonym 
  ; 
  Bifida, 
  Davidson, 
  1882. 
  

   Shells 
  small, 
  oval, 
  concavo-convex; 
  surface 
  with 
  a 
  few 
  sparse, 
  

   coirse 
  plications, 
  crossed 
  by 
  fine, 
  often 
  imbricating, 
  concentric 
  

   lines. 
  Pedicle-valve 
  with 
  a 
  conspicuously 
  arched 
  dorsum 
  ; 
  

   brachial 
  valve 
  with 
  a 
  distinct 
  median 
  depression. 
  On 
  the 
  

   interior 
  of 
  the 
  pedicle-valve 
  the 
  teeth 
  are 
  large 
  and 
  stout, 
  artic- 
  

  

  Fig. 
  37?, 
  Fig. 
  373. 
  

  

  The 
  brachidium 
  of 
  Anoplotheca 
  lepida, 
  Goldfu?s 
  (sp.). 
  

   Fig. 
  37?.— 
  A 
  lateral 
  view, 
  showing 
  the 
  relations 
  of 
  the 
  jugum 
  to 
  the 
  median 
  septum 
  and 
  ridge. 
  

   Fig. 
  373. 
  A 
  posterior 
  view. 
  

  

  ulating 
  in 
  deep 
  sockets 
  on 
  either 
  side 
  of 
  a 
  broad, 
  thickened, 
  

   slightly 
  elevated 
  hinge-plate. 
  The 
  volutions 
  of 
  the 
  spirals 
  are 
  

   few 
  and 
  the 
  cones 
  are 
  directed 
  toward 
  the 
  lateral 
  slopes 
  of 
  the 
  

   pedicle-valve. 
  The 
  jugum 
  arises 
  at 
  about 
  the 
  half-length 
  of 
  the 
  

   primary 
  lamellae, 
  the 
  lateral 
  branches 
  uniting 
  near 
  the 
  center 
  of 
  

   the 
  internal 
  cavity 
  and 
  forming 
  a 
  simple 
  upright 
  stem 
  whose 
  

   extremity 
  is 
  fitted 
  into 
  a 
  longitudinally 
  grooved 
  callous 
  in 
  the 
  

   pedicle- 
  valve. 
  In 
  the 
  brachial 
  valve 
  is 
  a 
  strong 
  median 
  septum 
  

  

  53 
  

  

  