GLASS XXII. ORDER V. 67 



Marcliantla. Capsules peduncled, bursting at their 

 summits : seeds attached to elastic fibres : the capsules 

 are placed beneath umbrella-like stars or cones. (It a- 

 grees with some species of jungerniannia in external ap- 

 pearance, but it is of a much firmer texture. The frond 

 is always leafy, lobed, .furnished with a strong midrib 

 and beset beneath with villous roots. The disk of the 

 leaf consists of a beautiful green net- work.) In the 

 spring one of the leading species sends up ovate anthers 

 or buds on pellucid filaments from the disk of the fVond. 

 Near the middle of the summer the umbrellas appear, 

 bearing tj^e fruit on or under the rays. 



ORDER IV. ALGAE. 



Fucus. Germs imbedded in the gelatinous substance 

 of the frond, aggregate : seeds produced in clustered tu- 

 bercles, which burst at their summits. 



Uh'd. Frond niembranaceous or gelatinous : fruit in 

 semi-transparent visicular membranes within the sub- 

 stance or under the general cuticle of the frond, either 

 solitary or clustered. 



Conferva. Consisting of herbaceous tubes or fibres, 

 generally separated within by transverse partitions : 

 seeds scattered through the joints, or contained in solita- 

 ry closed tubercles attached to the tubes or fibres. 



ORDER V. LICUEXES. 



Lecidea. Spangles sessile, with a flattish or convex 

 disk : frond various, crustaceous ; uniform and limited, 

 scattered and indeterminate, leafy, membranous, or stel- 

 late. 



Ghfrophora. Buttons superficial, flattish : frond leafy, 

 peltate, between membranous and leafy. 



Punnelia. Shields superficial or elevated, thick or sub- 

 membranous* flattish, convex or concave, crowned with 

 a Tree accessory border : frond various, crustaceous, 

 leaty, branched or lariniated, cartilaginous, membran- 

 ous or gelatinous. A vast genus. One of its best char- 

 a< I -i-a is that the shield has no border of its own sub- 

 si (i. e ; but ahvays has an accessary one of the substance 

 Oi die crust. 



Usnca> Orbs sub-coriaceous, flattened, peltate, na- 

 ke and smooth on both sMes, mostly much dilated ; disk 

 first concave, then fiat, even, subsequently rather convex 



