﻿Report 
  of 
  the 
  State 
  Geologist, 
  

  

  1071 
  

  

  disk, 
  slightly 
  bilobed 
  in 
  front 
  and 
  extending 
  beyond 
  the 
  loop 
  

   for 
  one-third 
  of 
  its 
  length. 
  This 
  disk 
  is 
  bordered 
  by 
  cirri. 
  

  

  Figs. 
  534, 
  535. 
  Dyscolia 
  Wyvilhi, 
  Davidson 
  (sp.). 
  (Dayidsox.) 
  

  

  Type, 
  Dyscolia 
  Wyvittii, 
  Davidson 
  (sp.). 
  

  

  Distribution. 
  Eecent 
  (West 
  African 
  and 
  Caribbean 
  provinces). 
  

  

  Subgenus 
  Glossothyris, 
  Douville. 
  1880. 
  

  

  Shells 
  like 
  Liothyrixa 
  but 
  with 
  a 
  deep 
  median 
  sinus 
  on 
  the 
  

   brachial 
  valve. 
  Loop 
  short, 
  anterior 
  transverse 
  band 
  slightly 
  

   recurved. 
  

  

  Figs. 
  536-533. 
  Glossothyris 
  nucleata, 
  Sculotheim 
  (sp.)- 
  (Qcexstedt.) 
  

  

  (Type, 
  Glossothyris 
  nucleata, 
  Schlotheim 
  (sp.). 
  Jurassic.) 
  

  

  Pygope, 
  Link. 
  1830. 
  

  

  Synonyms 
  ; 
  A?iti?iomia,Csitullo, 
  1S50 
  ; 
  Pugites, 
  de 
  Haan, 
  1833. 
  

  

  Shells 
  normally 
  biconvex 
  when 
  young, 
  but 
  with 
  increasing 
  age 
  

  

  the 
  median 
  growth 
  of 
  the 
  valves 
  is 
  arrested, 
  and 
  by 
  the 
  continued 
  

  

  129 
  

  

  