282 HANDBOOK OF BRITISH HEPATIC^. 



broken up by deep pits communicating with 

 the air-cavities. Larger and lighter coloured 

 than R. glauca. 



Riccia crystallina, Linn. Sp. 1605 > Cooke 

 Hep. fig. 200 ; Lindenb. Mon. 437, t. xxii., 

 fig. 2. 



On banks and hedges on damp mould. 



var. a vulgaris. Fronds less deeply cut, 

 lobes obcordate, margin rather elevated, 

 crenate. 



Riccia pellucida, Hoffm. Germ. 96. (Plate 7, 

 fig- 94> 



var. /3 palustris. Fronds with linear laciniae, 

 apex less dilated, crenulately emarginate. 



Riccia crystallina |3, Hook. Muse. Brit. 212 ; 

 Eng. Fl. V., i, p. 98 ; Lind. Mon. t. xxii., 

 fig. 2. No. 9. Lichen palustris, Dill. Muse. 355, 

 t. 78, f. 12. (Plate 7, fig. 946.) 



Grows in more shady and moist situations than 

 R. glatica, has the frond 

 generally longer,broader, and 

 much thinner, nearly plane, 

 with the segments more 

 numerous, and very obtuse, 

 colour by no means glau- 

 cous, rather perhaps inclin- 

 196- ing to yellowish green. 



Fronds in orbicular tufts radiating from the centre, 

 when fresh of a remarkably crystalline appearance. 



