32 IUinoif< State Laboratonj of X(ffnr(il Histori/. 



G 



Thallus copiously reticulate and porose. IX. Cono- 



CEPHALUS. 



,^ Thallus obscurely reticulated. V. Duvalia. 



H^ 



Lobes of carpocephalura scarcely distinguishable from 

 the involucres I 



Lobes of carpocephalum clearly apparent K 



Thallus distinctly areolate and porose, squamigerous. 



I I XIL LUNTJLARIA. 



1^ Thallus rigid, indistinctly porose. XI. x^itokia. 



r Androecium peduncled; thallus large, thin, with a slight 



J^ 1 COsta. VIII. DUMORTIERA. 



1^ Androecium ( so far as known ) sessile L 



( Thallus very indistinctly porose. VII. Asterella. 

 L ^ 



( Thallus clearly porose M 



Carpocephalum 3-4 lobed, hemispheric or conoidal. IV. 

 Grimaldia. 



1^ Carpocephalum 2-4 divided to base. III. Sauteria. 



I. MARCHANTIA L. 



Plant dioecious. Carpocephalum peduncled, radiate or 

 lobed. Peduncles areolate, arising from a sinus in the apex of 

 the expanded forking thallus. Outer involucres alternate with 

 the rays, 2-valved, lacerate, membranous, enclosing several 

 1-fruited, 4-5-parted involucres. Calyptra persistent, fissured 

 at the apex. Capsule globular, exserted, pendulous, dehiscent 

 by several revolute segments or teeth. Spores smooth. Ela- 

 ters long, slender, attenuate at each end, bispiral. Androecium 

 peduncled, peltate, radiate or lobed. Thallus large, areolate, 

 porose, with a broad diffused midrib, densely rooting. Gemmae 

 lenticular, borne in a cup-shaped receptacle on the back of the 

 thallus. Named for Nicholas Marehant, a French botanist, 



d. irws. 



