932 Report or THE Strate Gxroraist. 
Order DIACAULIA or DISCINACEA, Waagen. 
Family Discinipx, Gray. 
Discinolepis, Waagen, 1885. Lingulodiscina, Whitfield, 1890. 
Paterula, Barrande, 1879. Orbiculoidea, d’Orbigny, 1847. 
Schizobolus, Ulrich, 1886. Schizotreta, Kutorga, 1848, 
Trematis, Sharpe, 1847. Lindstreemella, Hall, 1892. 
Schizocrania, Hall and Whitfield, 1875. | Roemerella, Hall, 1892. 
(fhlertella, Hall, 1892. 
Family SrpsonorreTip®, Kutorga, 1848. 
Acrothele, Linnarsson, 1876. Schizambon, Walcott, 1884. 
Linnarssonia, Walcott, 1885. Siphonotreta, de Verneuil, 1845. 
Discinopsis, Matthew, 1892. Orbicella, d’Orbigny, 1849. 
Acrotreta, Kutorga, 1848. Keyserlingia, Pander, 1861. , 
Conotreta, Walcott, 1889. Helmersenia, Pander, 1861. 
Mesotreta, Kutorga, 1848. 
Order GASTEROPEGMATA or CRANIACEA, Waagen. 
Family Cranium», King. 
Crania, Retzius, 1781. Craniella, Gthlert, 1887. 
Numulus, Stobceus, 1732. Cardinocrania, Waagen, 1885. 
Ostracites, Beuth, 1776. Ancistrocrania, Dall, 1877. 
Criopus, Poli, 1791. Cranopsis, Dall, 1871. 
Criopoderma, Poli, 1791. Craniscus, Dall, 1871. 
Orbicula, Cuvier, 1798. Pholidops, Hall, 1869. 
Orbicularius, Duméril, 1806. Craniops, Hall, 1859. 
Craniolites, Schlotheim, 1820. Pseudocrania, McCoy, 1851. 
Choniopora, Schauroth, 1854. Palzeocrania, Quenstedt, 1871. 
Sub-Class ARTICULATA, Huxley; or ARTHROPOMATA, 
Owen. 
Order Protremata,* Beecher. 
Family Kuroreinip%,t+ Schuchert. 
Kutorgina, Billings, 1861. _ |(?) Volborthia, von Moller, 1873. 
Schizopholis, Waagen, 1885. Iphidea, Billings, 1872. 
* In employing as the fundamental divisional distinction in the Articulata, 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 the deltidium, the spon- 
dylium, or both. 
+ Mr. Schuchert includes under this family term two genera, Kutorgina and Schizopholis, 
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. 
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