314 The Ohio Naturalist. [Vol. V, No. 6, 



IF. Leaves complicate-liiloljed. 19. 



Leaves not complicate-bilobed. 20. 

 If. Perianth oval, scarcely or not compressed, plicate; mouth denticu- 

 late. Diplophyllnm. 

 Perianth dorsally compressed, mouth truncate, bilabiate, decurved. 



Scapania. 



20. LTnderleaves present (Plagiochila and Cephalozia mav be sought 



here). 21. 

 L^nderleaves none or usually none. (Odontoschisma may be sought 

 here). 20. 



21. Leaves bilobed, bidentate or emarginate. 22. 

 Leaves entire (sometimes retuse). 25. 



22. Leaves emarginate; perianth connate with the calyptra. Harpanthus. 

 Leaves bilobed or bidentate; perianth free. 23. 



23. Underkaves 2-4-cleft or parted. Lophocolca. 

 Underleaves entire or nearly so. 24. 



24. Involucral leaves 2, connate at base, entire. Stems without runners. 



Leaf-cells roundish, 5-7-angular, cell walls much thickened, each 

 cell appearing as if surrounded by about 6 smaller, 3 (or more)- 

 angular ones. Mylia. 

 Involucral leaves 3-ranked, bifid or bilobed. Stems with runners. 

 Leaf cells round, surrounded by much thickened walls. 



Odontoschisma. 



25. Underleaves 2-4-parted. Chiloscypkus. 

 Underleaves subulate, fugacious. Jvingermatiivia. 



26. Leaves bifid or bilobed. 27. 



Leaves entire (sometimes retuse) or spinulose-dentate. 28. 



27. Perianth triangular .prismatic, the contracted mouth dentate. 



Cephalozia. 

 Perianth oval-oblong, plicate, mouth denticulate. J ungerwiannia. 



28. Leaves entire (sometimes retuse). 29. 



Leaves spuinlose-dentate, rarely entire, the dorsal margin reflexed; 

 perianth compressed. Plagiochila. 



29. Perianth cylindrical, wider above, truncate, depressed, with orifice 



prominently umbilicate, ciliolate. Liochlaena. 

 Perianth compressed or terete, usually carinate, mouth entire or 

 toothed. Jiuigcrmannia. 



30. Capsule splitting into 4 regular valves (Jungermanniaceae). 31. 

 Capsule not splitting into 4 regular valves. 35. 



31. Thallus with distinct costa. 32. 

 Thallus with indistinct costa or none. 34. 



32. Thallus villous throughout or hairy (ciliate) on marign and midrib 



beneath. Metzgcria. 

 Thallus smooth. 33. 



33. Perianth long tubular; thallus mostly simple with sinuate or undulate 



margins, transparent, without inside cavities. Pallavicinia. 

 Perianth none; thallus dichotoinous or radiate with pinnatifid mar- 

 gins, opaque, with inside cavities filled with green cells. Blasia. 



34. Thallus mostly simple or forked, with thick margin. Sporogonium 



rising from the underside near margin. Elaters persistent on tip 

 of valves. Aneura. 

 Thallus mostly palmatifid or pinnately lobed with thin margin (one 

 layer of cells). Sporogf)nium rising from tlie up])er surface. 

 Elaters persistent in the centre of the ca])sule. Pcllia. 



35. Capsules solitary, more or less perfectly 2-valved (sometimes rup- 



turing irregularly), linear (Anthocerotaceae). 30. 

 Capsules aggregate, pendant from the underside of a peduncled disk 

 or cruciately arranged in 4 horizontal segments or sessile on the 

 thallus or immersed in it. 37. 



