Rice I A, 485 



Obs. — This is the commonest species of the genus, and is 

 easily recognised by its glaucous green colour, the same on both 

 sides. Some hepaticologists consider Rlccia minuiia L. to be the 

 same as It. sorocarpa Bischoff, but as probably all small forms of 

 Biccia would be included under this name, I prefer to follow 

 Bischoff, as he was the first to correctly and fully describe and 

 figure the species, and I retain the small form which cannot be 

 separated as a species from R. (jlanca as var. riiiiiiina. This must 

 not be confounded with the plant described and figured by 

 Lindenberg, which is purple beneath (Lindenb. Mon. Eiccia, 

 p. 427, t. XX (1836) ). 



DESCRIPTION OF Plate CCXVL — Figs. 1, 2. Plants natural 

 size (Bischoff). 3, 4. Ditto magnified (ditto). 5. Ditto, var. 

 major x 2 (ditto). 6. Ditto, var. minima, natural size (Fowlshaw 

 Moss, G-. Stabler). 7. Ditto x 11 (ditto). 8. Ditto, var. major 

 (Baden, Jack). 9, 10. Cross-section of fronds x (Bischofl'). 

 11-13. Ditto X IG (Fowlshaw Moss, G. Stabler). 14. Portion 

 of rootlet X 200 (Hoft'meister). 15, Antheridium x (j4 

 (Fowlshaw Moss, Gr. Stabler). 16. Convex surface of spores, 

 highly magnified (ditto). 



2. B-iccia crystallina, Z. 



Lichen palusfris, Dill. Hist. muse. p. 5^)5, t. 78, f. 12 (1741). 

 Riccia crystallina, Linn. Sp. pi. 1605 (17r)o). 



Monoicous, forming rosettes, closely attached to the ground, 

 small, pale or yellowish green on both sides, crystalline. Fronds 

 flat, circular or wedge-shaped, segments bilobed or furcate, 

 obcordate, margin slightly crenate, sometimes slighth^ raised^ 

 antical surface pitted, epidermic cells 6-sided ; cross-section shows 

 frond to be of equal thickness and full of air-cavities ; radiculose, 

 rootlets few, long, hyaline. Capsule embedded in the frond, 

 spherical, brown ; style conical, projecting, covered with a hyaline 

 or faintly purple calyptra. Spores roundish-angular, reddish- 

 brown, reticulate, 6-8 lumen across each face, walls raised, 



