on the Organic Composition of Chalk and Chalk Marl. 381 



Families and Genera, with their characteristics. According to 

 this view the Bryozoa comprise four Orders, Poli/thalamia, 

 Gymnocorcc, Thallopodia and Scleropodia ; the Polythalamia 

 being divided into Monosomatia (single-bodied), consisting of 

 fifty-six genera, and Polj/sonatia (many-bodied or polyparian), 

 composed of twenty-two genera, forming altogether seventy- 

 eight genera of Polythalamia. The following Table exhibits 

 the general arrangement. 



Bryozoa. 

 Animalia asphycta, tube cibario simplici, sacciformi aut tubuliforini, vera 

 corporis articulatione nulla aut sensini nunierosiore, corporis forma 

 scmmis aut novis articulis accedeiitibus sensim aucta, hinc indefinila, 

 nunquam spoiite dividua, omnia et singula verisiiniliter periodice ovi- 

 para, ideoque hermaphrodita. 



Ordo I. — Polythalamia. 

 Libere vagantia et loricata. 



Monosomatia. 

 Familia I. 



Familia II. 



Familia III. 



Familia IV 



Familia V. 



MiLIOLINA. 



Genera 2. ? Miliola, ? Gromia. 



NoDOSARINA. 



Gen. 11. Glandulina, Mucronina, Nodosaria, Ortho- 

 cerina, Dentalina, Lingulina, Frondicularia, 

 Rimulina, Vaginulina, Planularia, Marginu- 

 lina. 

 Textularina. 



Gen. 6. Bigenerina, PDimorphina.Textularia.Gram- 

 mostomum {Vulvularia), Polymorphina, Vir- 

 ffulina. 



UVELLINA. 



Gen. 11. 



ROTALINA. 



Gen. 22. 



Guttulina (et Globidina), Uvigerina, Bulimi- 

 na, Valvulina, Rosaliiia, Clavulina, Globige- 

 rina, Pyrulina, Sphaeroidina. 



Familia VI. 



Po/i/snmatia. 

 l''amilia VII. 



Familia VIII. 

 Familia IX. 

 Familia X. 



Operculina, Soklania, Planorbulina, Rotalia, 

 Trochulina, PSpirulina, Calcarina, Pleurc- 

 trema, Planulina, Discorbis,Omphalophacus, 

 PGyroidina, Truncatulina, Lenticnlina, No- 

 nionina, Cristellaria, Siderolina, Dendritina, 

 Robulina, Anomalina, Saracenaria, Cassidu- 

 lina. 

 Pltcatilia. 

 Gen. G. Bilociilinu, Spiroloculina, Triloculina, Arti- 

 culina, Quiuqueloculina, Adelosina. 



Asterooiscina. 



Gen. 5. Asterodiscus, Lunulites, Orbitulites, Cnpii- 

 laria, Fluslrella. 

 Soritina. 



Cicn. 2. Sorites, Ampiiisorus. 

 Frumdntarina. 



Gen. 3. ? Ductylopora, ? Ovulites, ? Polytripe. 

 Helicosorina. 



Gen. .'>. Pencroplis, Pavonina, Vertebralina, Orbicu* 

 lina, ? Heterostegina. 



