NICKLES AND BASSLEK.] CLASSIFICATION. 13 



HISTORY OF CLASSIFICATION. 



The first serious attempt at a classilication of the l)ryozoa was made 

 by LVOi'bigiiy.' D'Orbigiiy's wide acquaintance with recent and 

 fossil bryozoa has perhaps been equaled by no subsequent writer. 

 But the system he devised was so largely artificial and burdened with 

 so perplexing a nomenclature that it failed to gain acceptance. The 

 labors of Nitsche, Allman, and Busk have fixed the principal groups. 

 To Nitsche' is due the division into the two groups Ectoprocta and 

 Entoprocta, the latter containing only the two singular genera Pedi- 

 cellina and Loxosoma. Allman'' formed the orders Phylactola?niata 

 and Gj^mnolsemata, the latter including most of the bryozoa and all 

 forms capable of preservation as fossils. Busk's suborders Chilo- 

 stomata, Cyclostomata, and Ctenostomata * have been generally 

 accepted. To these suborders Mr. Ulrich, in 1882,'^ added the sub- 

 order Trepostomata, to include, besides uncontested bryozoa, a num- 

 ])er of forms which had been generally regarded as corals; and Mr. 

 G. R. Vine, in 1883,® added the suborder Cryptostomata. 



Recently Dr. J. W. Gregory^ has raised these suborders to the 

 rank of orders, and for the Chilostomata proposes live suborders: 

 the Stolonata, with the families ^'EteidjB, Eucratiid^, and Chlidoniidas; 

 the Cellularina, with the families Cellulariidas, Bicellariida?, Episto- 

 miidffi, Catenicellidfe, and Bifaxariidaj; the Athyriata, with the fami- 

 lies Farciminariidse, Flustrida?, Membraniporidse, Cribrilinidie, Micro- 

 porida?, Steganoporellidaj, and Cellariidie; the Schizothyriata, with 

 families Schizoporellida^, Adeonellida?, and Microporellidte; and the 

 Holothyriata, with the families Lepraliidffi, Celleporida?, and Smit- 

 tiid». For the Cyclostomata he proposes three suborders: the Articu- 

 lata, with one family, the Crisiids; the Tubulata, with the families 

 Tubuliporida?, Entalophorida^, Idmoneidse, Hornerid^, Fascigerida, 

 Osculiporida?, and Theonoidaj; and the Dactylethrata, with the fami- 

 lies Clausidai and Reticuliporida?. 



Zittel, in his excellent Handbuch der Pal^eontologie (Leipzig, 1880), 

 utilizing the labors of Nitsche, Allman, Busk, Smitt, Hincks, Reuss, 

 Stoliczka, and others, gave probably as good a classification as could be 

 gi\'en at that time. We have followed in the main the classification 

 in the English edition of Zittel's Textbook of Palajontolog}^ (Macmil- 

 lan & Co., London, 1896); the section of this edition relating to the 

 bryozoa was revised and in large part rewritten by Mr. E. O. Ulrich. 

 Dei)artures from this classification are based mainly upon later, hitherto 

 unpublished, studies of this author. 



' Pal. Fiiinc. Terr. Cr6tac<5, V, 1850-1. 



^Zeitschrift fiir wi.ssenschaftlic'he Zoologic, XX, 1869. 



^Monograph of the Freshwater Polyzoa, 18.30, p. 10. 



■•British Mu.seum Catalogue of Marine Polyzoa, 1862. 



^ Jour. Cincinnati Soe. Nat. Hist., V, p. 1.51. 



6 Kept. Brit. Assoc. Adv. Sci., p. 196. 



' Trans. Zool. Soc. Loudon, XIII, 1893, and British Museum Catalogue of Jurassic Bryozoa, 1896. 



