Cephalozia. 



1. Prothallium slender, linear or almost filiform, consisting of only a 

 single (more rarely in part of a double) series of cells ; eitlier simple or 

 subramose ; often passing at the apex insensibly into the stem, and per- 

 sisting a long time. 



2. Plants usually small and tender, in only a few species rather 

 robust ; of almost all shades of green and brovrn, or whitish and pellucid, 

 sometimes tinged with rose ; growing in depressed matted tufts, or flakes, 

 or creeping over Sphagna and other mosses. 



3. Ste77is usually prostrate or jpi'ocumbent, leafy throughout, or rhi- 

 zomatous and leafless at the base — very rarely with the leaves reduced 

 to mere scales — still more rarely frondose ; branches all jjostical, springing 

 fi'om the underside of the stem, and axillary to the underleaves where 

 any exist ; radicles usually copious, pale and slender. 



4. Leaves mostly succubous, in a few species transverse, in a very 

 few subincubous ; horizontal or assurgent, never deflexed, roundish, or 

 subquadrate, or cuneate, rarely lanceolate, very seldom plane, usually 

 concave, and in most species somewhat compHcate and bilobed (but 

 never divided to the very base, nor with capillary lobes), in a very few 

 species undivided or variable at the apex ; margins uniforynly lolane or 

 subincurved — never convex or recurved — very mostly quite entire, but in a 

 few species toothed. Reticulatioyi in the typical species lax and pellucid, 

 in a few species denser and subopaque ; cells often subquadrate, in the 

 subgenus Alobiella, large and oblong or rectangular ; cell- walls mostly 

 thin, rarely conspicuously thickened at the angles ; cuticle smooth or 

 scaberulous. 



5. Underleaves much smaller than the side leaves, and oftener un- 

 divided at the apex, but in some species subdentate at the margin ; en- 

 tii'ely absent from many species [except in the involucre, where they 

 exist in every Cejjhalozia.'] 



6. Infiorescence dioicous or autoicous — very rarely X3aroicous. An- 

 dracia amentiforn, occupying the whole, or only a part, of a branch, 

 rarely terminal on the stem. Bracts in many x^ah-s, leafy (even where 

 there are no stem-leaves) bifid, uniformly monandrous. 



7. Gynacia capitate, usually seated on an abbreviated branch (i.e. 

 cladocarjjous), but sometimes terminal on longer branches or on the main 



