BRITISH SILURIAN BRACHIOPODA. 



85 



Distribution of Spiral-bearing Brachiopoda in time. 



1. Family Spiriferid^, King, 1846. 



Spirifera, Sow., 1815 



Cyrtia, DaZwiaw, 1828 



Syringotbyris, Winchell, 1863 



Cyrtina, Bav., 1S58 



Spiriferina, (^'OrS., 1847 



Suessia, Besl., 1854 



Eeticularia, M'Coy, 1844 : 



2. Family NucLEOSPiRiDiE, Bav,, 1881 



rNucleospira, Hall, 1839 



\ Retzia, King, 1850 



(Meristina, Hall, 1867 



? Trematospira, Zffl//, 1857 



Dayia, Bav., 1881 



Uncites, 2>e/r«Kce, 1825 



3, Family Athyrid^, Phillips, 1841. 



Athyris, WCoy, 1844 



Kayseria, Bav., 1882 



Whitfieldia, Dat>., 1881 



Bifida, Dffv., 1882 



Meristella, .ffa/Z, 1859 



Merista, Suess., 1851 



4. Family ATRYPiniE, Ball, 1877. 



Atrypa, Balman, 1828 



Coelospira, H«//, 1863 



Tliecospira, Zugmayer, 1 880 



Anoplotheca, Sandb., 1855 



Koninckina, Suess., 1853 , 



Koninckella, Munier-Chalmas, 1880 



Davidsonia, Bouchard, 1847 



Glassia, Bav., 1881 



Zygospira, Hall, 1862 



^ This Table of classification is provisional, for much still remains to be discovered and explained. 

 The details of classification, upon which Mr. Glass and myself are still at work, will be again referred to 

 in the continuation of this Supplement. 



