﻿836 
  Forty-seventh 
  Report 
  on 
  the 
  State 
  Museum. 
  

  

  Order 
  DIACAULIA 
  or 
  DISCINACEA, 
  Waagen. 
  

   Family 
  Discinidjs, 
  Gray. 
  

  

  Discinolepis, 
  Waagen, 
  1885. 
  

   Paterula, 
  Barrande, 
  1879. 
  

   Schizobolus, 
  Ulrich, 
  1886. 
  

   Trematis, 
  Sharpe, 
  1847. 
  

   (Ehlertella, 
  Hall, 
  1892. 
  

  

  Lingulodiscina, 
  Whitfield, 
  1890. 
  

  

  Schizocrania, 
  Hall 
  and 
  Whitfield, 
  1875. 
  

   Orbiculoidea, 
  d'Orbigny, 
  1847. 
  

   Schizotreta, 
  Kutorga, 
  1848. 
  

   Lindstroemella, 
  Hall, 
  1892. 
  

   Roemerella, 
  Hall, 
  1892. 
  

  

  Family 
  Siphonoteetid^;, 
  Kutorga, 
  1848. 
  

  

  Acrothele, 
  Linnarsson, 
  1876. 
  

   Linnarssonia, 
  Walcott, 
  1885 
  . 
  

   Discinopsis, 
  Matthew, 
  1892. 
  

   Acrotreta, 
  Kutorga, 
  1848. 
  

   Conotreta, 
  Walcott, 
  1889. 
  

   Mesotreta, 
  Kutorga, 
  1848. 
  

  

  Schizambon, 
  Walcott, 
  1884. 
  

   Siphonotreta, 
  de 
  Verneuil, 
  1845. 
  

   Orbicella, 
  d'Orbigny, 
  1849. 
  

  

  Keyserlingia, 
  Pander, 
  1861. 
  

   Helmersenia, 
  Pander, 
  1861. 
  

  

  Order 
  GASTEROPEGMATA 
  or 
  CRANIACEA, 
  Waagen. 
  

  

  Family 
  Craniid^e, 
  King. 
  

  

  Crania, 
  Retzius, 
  1781. 
  

  

  Numulus, 
  Stoboeus, 
  1732. 
  

   Ostracites, 
  Beuth, 
  1776. 
  

   Criopus, 
  Poli, 
  1791. 
  

   Criopoderma, 
  Poli, 
  1791. 
  

   Orbicula, 
  Cuvier, 
  1798. 
  

   Orbiculavius, 
  Dumeril, 
  1806. 
  

   Craniolites.' 
  Schlotheim, 
  1820. 
  

  

  Choniopora, 
  Schauroth, 
  1854. 
  

   Craniella, 
  GEhlert, 
  1887. 
  

   Cardinocrania, 
  Waagen, 
  1885. 
  

   Pholidops. 
  Hall, 
  1869. 
  

  

  Craniops, 
  Hall, 
  1859. 
  

   Pseudocrania, 
  McCoy, 
  1851. 
  

   Palseocrania, 
  Quenstedt, 
  1871. 
  

  

  Sub-class 
  AKTICULATA, 
  Huxley 
  ; 
  ARTHROPOMATA, 
  Owen. 
  

   Order 
  PROTREMATA,* 
  Beecher. 
  

  

  Family 
  KuroRGiNn),E,t 
  Schuchert. 
  

  

  Kutorgina, 
  Billings, 
  1861. 
  

   Schizopholis, 
  Waagen, 
  1885. 
  

  

  Volborthia, 
  von 
  Moller, 
  1873. 
  

   Iphidea, 
  Billings, 
  1872. 
  

  

  * 
  In 
  employing 
  as 
  the 
  fundamental 
  divisional 
  distinction 
  in 
  the 
  ArticuJata, 
  the 
  presence 
  of 
  

   the 
  deltidium 
  or 
  the 
  deltidial 
  plates, 
  the 
  term 
  Protremata 
  covers 
  better 
  than 
  any 
  other 
  those 
  

   genera* 
  in 
  which 
  the 
  primitive 
  pedicle-covering 
  is 
  represented 
  by 
  either 
  tbe 
  deltidium, 
  the 
  

   spondylium, 
  or 
  both. 
  

  

  t 
  Mr. 
  Schuchert 
  includes 
  under 
  this 
  family 
  term 
  two 
  genera, 
  Kutorgina 
  and 
  Schizophoijs 
  

   which 
  have 
  usually 
  been 
  regarded 
  as 
  belonging 
  to 
  the 
  Inarticulate 
  sub-class. 
  The 
  reasons 
  for 
  

   the 
  installation 
  of 
  these 
  as 
  the 
  elementary 
  family 
  of 
  the 
  Articulata 
  are 
  given 
  elsewhere. 
  

  

  