scHucHKKT.] CLASiSIFICATION OF PROTREMATA. 131 



Supeiiiimily CRANIACEA Waagen, 1885.' 

 Gasteropegmata Waagen, 1885. 



Cemeuted calcareous Neotremata without pedicle or aual opeuiugs 



at maturity. 



Family CRAN^D^E King, 1846. 



OrbiculiP Deshayes, 18.30; Cianiadie Gray, 1810. 



Craiiiacea with the pedicle functioual probably ouly during nepionic 

 growth. - 



Crania lietzius, 1781. 



Numuiulus Stoeboeus, 1732. 



Ostracites Beuth, 1776. 



Criopiis Poll, 17U1. 



Criopoderuiii Poli, 1795. 



Orbicula Cuvier, 1798 (not Sowerby, 



1830). 

 Orbicularius Dumeril, 1806. 

 Craniolitos Schlotheim, 1820. 

 Discina Turtou, 1832 (not Lamarck, 



1819). AA6tA^^^ n 



Criopolisderiiia Aj; ' .ta»iH , 18*<f. 



Craniella (Ehlert, 1888. 

 Cardinocrauia Waagen, 1885. ^ 

 Ancistrocrania Dall, 1877. 



Cranopsis Dull, 1871 (not A. Adams). 

 Craniscus Dall, 1871. 



Siphouaria Queustedt, 1851 (not 

 Sowerby). 



Pholidops Hall, 1800. 



Craniops Hall, 18.59. 

 Pseudocrania McCoy, 1851. 

 Palajocrania Quoiiatodt, 1871. 



Chonioi)ora .Schauioth, 1854. 



Order PROTREMATA Beecher, 1891. 



Derived, articulate Brachiopoda, with tlie pedicle opening restricted 

 to the ventral valve throughout life or during early growth. Prodel- 

 tidiuni originating on the dorsal side of the body wall in the cephalula 

 stage, and later anchylosed to the ventral shell, thus initiating the 

 development of a deltidium. Pedicle aperture moditied by the delti- 

 dium. Brachia unsupported by a calcareous skeleton except in the 

 Pentameracea where there are crura. 



Superfamily STROPHOMENACEA Schuchert, 1896. ^ 



Lineicardiues (partim) and Denticardines (partim) Broun, 1862; Apbaneropegniata 

 (partim), Prodnctarea, Coralliopsida, and Kampylopegmata (partim) Waagen, 1883; 

 Eleutheiobranchlata (partim) Neumayr, 1883; Cryptobracbia (partim) Gray, 1848; 

 Tbecacea Scbiicbert, 1893. 



Primitive Protremata without spondylia and cruralia. 



Family KUTORGINID^ Schuchert, 1893. 



Primitive Strophomenacea with incipient cardinal areas, great del- 

 thyrial opening, and very rudimentary articulating processes and 

 deltidium. 



Kutorgina Billings, 1861 (emend ?Schizopholis Waagen, 1885. 

 Walcott). 



'The writer believes that when the young growth stages of Crania are studied it will be shown 

 that the Craniacea have the superfamily characters of Acrotretacea rather than those of Discinacea. 

 ^Text-book of Paleontology, by Zittel and Eaatman, 1896, p. 312. 



