600 Proceedings of the Royal Irish Academy. 



Involucre cup-shaped, short, lacerate. Cole- 

 sule wanting. Calyptra exserted, glo- 

 bous. Inflorescence dioecious. Capsule 

 4-valTed. of thick texture. Elaters per- 

 sistent. Antheridia immersed in recep- 

 tacles, proceeding from margin of frond, . Eiccaedia. 



B. Cleistocaep^. 



Sub-tribe 10. Sph^kocaepe^. 



Capsule without valves, globular, free, im- 

 mersed in the membranous frond. Elaters 

 and Colesule wanting, .... SpHiEEOCAEPus. 



Sectiois' III. Anthocerotace^. 



Capsule solitary, filiform, bivalved, stalked, with a free central pla- 

 centation. 



Family 1. Anthoceeote^e. 



Colesule tubulose. Capsule 2-valved, linear, 

 elongate, pedicelled, with a free central 

 placentation. Elaters imperfect, . . Anthoceeos. 



Section I. Maechantiace.3i:. 

 A. ScHizocAEPiE, Lindberg. 



Family 1. Maechantie^. 



Perennial plants with spreading fronds, more or less camose, lying flat 

 on the ground, and clothed more or less beneath with imbricating 

 scales, which are frequently coloured, among which numerous- 

 rootlets issue. Dioecious for the most part. Female receptacle 

 raised on a peduncle, springing from near the apex or back of the 

 frond, radiate or capitate, with loculi. Colesules present or want- 

 ing. Male receptacle elevated or sessile, smooth or hairy. 



Maechantia, Linneus. 



Male receptacle pedunculated, furnished with scales beneath. Female 

 receptacle rayed, involucres alternate with the rays, 1-3 flowered j 

 bivalved. Colesule 4-5 cleft. Calyptra bursting, remaining within 

 the colesule. 



Marchantia polymorpha, Linn. Fertile receptacle deeply cut, star-like, 

 into eight or ten divisions. Male receptacle peltate, undivided. 



