INTRODUCTION. XI 



8. Sagenaria. Stem without joints, or furrows, covered with conical rhom- 



boidal tubercles disposed in quincunx, having at their upper extremity 

 an impression in the form of a disk. 6 



9. Stigmaria. Stem without joints, or furrows; impressions rounded, 



distant, disposed in quincunx/ 



10. Lycopodites. Leaves linear, or setaceous, without ribs, or traversed by a 

 single rib, inserted all round the stem, or in a double row. 



The author subdivides this genus into four sections, as follows : 



A. Leaves narrow, lanceolate, inserted in a regular manner all round a 



stem having the characters of sagenaria. 



B. Leaves setaceous, inserted in a double row only; stem not reticulated. 



These he considers as the proper lycopodites. 



C. Leaves broad, without any apparent ribs, inserted irregularly all round 



the stem. These differ much from the rest of the genus. 



D. Leaves blunt, short, closely applied to the stem. 



11. Filicites. Frond disposed on a flat surface, symmetrical; secondary rib 

 simple, forked, or rarely anastomosing. 



These M. Brongniart further divides into five sub genera : 



A. Glossopteris. Frond simple, not jagged, traversed by a single mid 



rib, without distinct secondary ribs. 



B. Sphenopteris. Pinnules wedge shape, rounded or lobed at the ex- 



tremity ; ribs palmate or radiating from the base of the pinnule. 



C. Neuropteris. Pinnules rounded, not lobed, nor adhering to the rachis 



by their base ; ribs scarcely visible beyond the base, in general very 

 distinct, and two forked. 



D. Pecopteris. Frond pinnatifid ; pinnules adherent by their base to 



the rachis, traversed by a mid rib ; secondary ribs pinnate. 



• The stems of this genus are referrable, in the opinion of M. Brongniart to those of plants belonging 

 to the family of lycopodiaceae, notwithstanding the great difference of size between them, and those of the 

 recent plants of that natural order. 



1 These stems belong, in M. Brongniart's opinion, rather to plants of the natural order of aroideae, 

 than to the euphorbiaceae, or to the palms to which they had been ascribed by other authors. 



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