180 Brongniartf Sur hs Vegetaux lossilts. 



Genera. 1. Culmites. Stems articulated smooth, only one 

 impression at each articulation. They sometimes want 

 this impression, but have then many cicatrices on the in- 

 ternodes. They are considered analogous to the grasses 

 and the last variety to the creeping roots of grasses. They 

 are found only in the coarse limestone of the superior sedi- 

 ment near Paris. 



2. Calamites. Stems articulated, regularly striated, im- 

 pressions rounded small numerous, forming a ring around 

 each articulation, or sometimes v^anting. They are refer- 

 red to the Genus Equisetum, to which they are at least anal- 

 ogous, although arborescent in size. They are found only 

 in the coal formations, and in the copper mines of Catha- 

 rineburgh. 



3. Syringodendron. Stems channelled not articulated, im- 

 pressions punctiform or linear, disposed in a quincunx. 

 They cannot be satisfactorily allied to any known plants. 

 Found only in the coal formations. 



4. Sigillaria. Stems channelled, not articulated, impres- 

 sions in the form of a disc disposed in a quincunx. 



5. Clathraria. Stems neither channeled nor articulated, 

 impressions in the form of rounded discs disposed in a quin- 

 cunx. 



These two Genera are referred to the Arborescent 

 ferns-:-found only in the coal formations. 



6. Sagenaria. Stems neither channeled nor articulated, 

 covered with rhomboidal conic tubercles, disposed in a 

 quincunx, bearing at their summit an impression in the 

 form of a disc. 



These are referred to the Lycopodia, although arbores- 

 cent. Found only in the coal formations. 



7. Stigmaria. Stems neither channeled, nor articulated, 

 impressions rounded, far apart, disposed in a quincunx. — 

 Their analogy is doubtful, but considered nearest to the ar- 

 borescent AroidaB, viz. the Dracontia, Pothos, &c. Found 

 only in coal formations, and in the copper mines of Catha- 

 rineburgh. 



Class III. Stems and leaves united, or leaves insulated. 



Genera. 1. Lycopodites. Leaves linear or setaceous, 

 without nerves, or traversed by a single nerve, inserted all 

 around the stem or on two rows. There are four very dis- 

 tinct sections. 1. Leaves narrow, lanceolate, inserted all 



