﻿1054 
  Forty-seventh 
  Report 
  on 
  the 
  State 
  Museum. 
  

  

  the 
  deltidial 
  plates 
  have 
  almost 
  invariably 
  been 
  displaced. 
  The 
  

   muscular 
  scars 
  of 
  this 
  valve 
  are 
  deep 
  and 
  sharply 
  denned, 
  but 
  

   restricted 
  to 
  the 
  posterior 
  portion 
  of 
  the 
  shell. 
  In 
  the 
  brachial 
  

   valve, 
  the 
  hinge-plate 
  is 
  elevated 
  into 
  a 
  stout, 
  erect, 
  subcylindrical 
  

   cardinal 
  process, 
  whose 
  posterior 
  face 
  is 
  grooved 
  and 
  striated. 
  

   Brachidium 
  extending 
  for 
  nearly 
  the 
  entire 
  length 
  of 
  the 
  valves 
  ; 
  

   jugal 
  processes 
  depressed, 
  long 
  and 
  convergent; 
  descending 
  

   lamellae 
  arising 
  at 
  an 
  angle 
  from 
  the 
  crura 
  ; 
  ascending 
  lamellae 
  

   deeply 
  reflected. 
  Impressions 
  of 
  the 
  adductor 
  muscles 
  long, 
  

   narrow 
  and 
  obscure. 
  

  

  Type, 
  Megalanteris 
  Archiaci, 
  de 
  Verneuil. 
  

  

  Distribution. 
  Devonian. 
  

  

  Enantiosphen, 
  Whidborne. 
  1893. 
  

   Shells 
  large, 
  with 
  smooth 
  biconvex 
  valves 
  having] 
  broadly 
  

   introverted 
  margins 
  ; 
  general 
  external 
  aspect 
  as 
  in 
  Megalanteris. 
  

   Interior 
  with 
  a 
  strong 
  ventral 
  median 
  septum. 
  

  

  Fig. 
  493. 
  Fig. 
  494. 
  

  

  Figs. 
  493, 
  494. 
  Enantiosphen 
  Vicaryi, 
  Davidson 
  (sp.) 
  

  

  (Davidson.) 
  

  

  Type, 
  Enantiosphen 
  Vicaryi, 
  Davidson 
  (sp.) 
  

   Middle 
  Devonian 
  (Torquay). 
  

  

  Cryptonella, 
  Hall. 
  1861. 
  

  

  (Plate 
  52, 
  figs. 
  16-23.) 
  

  

  Yalves 
  subequally 
  convex 
  ; 
  elongate-oval 
  in 
  outline, 
  broadest 
  

  

  in 
  the 
  pallial 
  region. 
  Pedicle-valve 
  witn 
  prominent, 
  erect 
  or 
  

  

  slightly 
  incurved 
  umbo 
  ; 
  deltidial 
  plates 
  well 
  developed 
  ; 
  foramen 
  

  

  circular, 
  apical, 
  rarely 
  encroaching 
  upon 
  the 
  umbo, 
  or 
  becoming 
  

  

  112 
  

  

  