Order 3. =Fissidentaceæ.= Peristome as in the preceding ones. The leaves are arranged in two rows on the plagiotropic shoots; in _Fissidens_ the midrib of the leaf bears wing-shaped outgrowths. _Conomitrium, Fissidens._ Order 4. =Seligeriaceæ.= Peristome with 16 undivided teeth. Very small Rock-mosses. _Seligeria.--Blindia._ Order 5. =Pottiaceæ.= Peristome with 16 teeth, which are divided almost to the base, or with 32 teeth. Calyptra hood-like.--_Barbula (B. muralis, B. ruralis), Trichostomum, Leptotrichum.--Ceratodon purpureus.--Distichium.--Pottia._ Order 6. =Grimmiaceæ.= The leaf-cells are often papillose; in the upper portion of the leaf, small, and of roundish shape. The calyptra is most frequently hood-like or conical. _Eucalypta._--_Orthotrichum_, often with short-stalked capsule, is found on trees.--_Coscinodon._--_Hedwigia._--_Grimmia_, _Racomitrium_.--_Cinclidotus._ Order 7. =Schistostegaceæ.= The stems are of two kinds (see above); _Schistostega osmundacea_, in caves, has a bright emerald protonema. Order 8. =Splachnaceæ.= The capsule has a large, collar-like neck (see above). _Splachnum_ (especially on manure). Order 9. =Funariaceæ.= Capsule pear-shaped. _Funaria_ (_F. hygrometrica_ has a very hygroscopic seta, becoming twisted when dry, and straightening with moisture); _Physcomitrium_; _Discelium_. Order 10. =Bryaceæ.= The capsule is thicker towards the apex; most frequently pendulous. _Philonotis_, _Bartramia_.--_Aulacomnium._--_Paludella Meesea._--_Mnium._--_Bryum_, _Webera_, _Leptobryum_. Order 11. =Polytrichaceæ.= Single peristome, formed by 16, 32, or 64 teeth. Leaves with longitudinal lamellæ on upper surface.--_Polytrichum_ has long, hairy calyptra. _Catharinea_ (_C. undulata_, in forests). Order 12. =Georgiaceæ.= Peristome with 4 teeth (see above). _Tetraphis_ (_T. pellucida_ has gemmæ). Order 13. =Buxbaumiaceæ.= Capsule asymmetrical; double peristome: the interior one conical, with 16 or 32 longitudinal folds.--_Buxbaumia_ (_B. aphylla_); _Diphyscium_. B. =Pleurocarpi.= Order 14. =Fontinalaceæ.= Long, floating Water-Mosses. _Fontinalis_ (_F. antipyretica_ is found in streams). _Dichelyma._ Order 15. =Hookeriaceæ.= _Pterygophyllum._ Order 16. =Leskeaceæ.= Dull-looking Mosses, with papillose or warted leaves.--_Thuidium_, _Thuja_-like with regularly arranged 1–3 doubly pinnate stems; _Anomodon_, _Leskea_. Order 17. =Pterogoniaceæ.= _Pterigynandrum filiforme_, etc. Order 18. =Fabroniaceæ.= _Anacamptodon._ Order 19. =Neckeraceæ.= Stems most frequently with flat, leafy branches. The leaves are smooth, never with longitudinal folds.--_Neckera._