HANDBOOK OF BRITISH HEPATICJE. 279 



Capsule dehiscing irregularly. Elaters absent. 

 Antheridia immersed in the frond. 



The British genera may be thus character- 

 ised : 



A. Without a proper involucre : 



Capsule immersed in the upper side of the 

 frond. Riccia. 



Capsule adnate to the inferior surface. 

 Ricdella. 



Capsule immersed in the frond, not protu- 

 berant. Ricciocarpus. 



B. With a proper involucre : 



Fruit free on the disc of the frond. Spharo- 

 carpus. 



GENUS 48. RICCIA, Mich. 



Involucre none. Fruit immersed in the 

 frond. Calyptra style- 

 bearing, style deciduous. 

 Sporangium globose, ir- 

 regularly erumpent. Ela- 

 ters none. Antheridia 

 naked on the superficies 

 of the frond, tubulous, 

 produced on the same or on other indi- 

 viduals. 



" Capsule sphaerical, immersed in the frond, 

 indehiscent, crowned with a style, which 

 alone is protruded." 



