428 SKETCH OP PALEOBOTANY. 



interesting are his notes on the Bibliolithes in which most of the dico- 

 tyledonous leaves, then known, are referred to. Of Palmacites he 

 describes fifteen species under regular systematic names. Of Casuari- 

 nites he gives five species ; of Oalamites, ten ; of Filicites, twenty- three ; 

 of Lycopodiolithes, five ; of Poacites, four; of Oarpolithes, fifteen, and of 

 Anthotypolithes, one. The science of paleobotany could therefore start 

 from this date with seventy-eight species described and figured. 



Count Sternberg, in his " Flora der Vorwelt," established a large num- 

 ber of genera, which he founded upon the most thorough investigation, 

 a large share of which have resisted the destructive agencies of subse- 

 quent research. Among these were Lepidodendron, Flabellaria, Annula- 

 ria, Noeggerathia, and Sphenopteris. His determinations were modest and 

 sound, and he was able only in a few cases to refer the fossil forms to 

 living genera, as in Osmunda, Asplenium, etc. But the most impor- 

 tant departure effected in this work was in establishing vegetable 

 paleontology for the first time upon a geognostic basis. He assumed 

 three periods of vegetatiou : (1) an insular period characterized by the 

 great coal plants ; (2) a period characterized by the predominance of 

 cycadean types, and (3) a period introduced by fucoidal remains and char- 

 acterized by dicotyledonous forms. It will be at once perceived that 

 these three periods correspond substantially with the Paleozoic, Meso- 

 zoic, and Ceuozoic ages of modern geology. 



Passing over the system of Martins, published in 1822,^i which, 

 though having merits, has been received with less favor, we now come 

 to that of Brongniart, the first draft of which also appeared in 1822.''*^ 

 In this memoir all fossil plants were divided into four classes, ex- 

 pressly so-called, viz., (1) stems whose internal organization is recog- 

 nizable; (2) stems whose internal structure is not recognizable, but 

 which are characterized by their external form; (3) stems joined to 

 leaves or leaves only ; (4) organs of fructification. The first class is 

 divided into Exogenites and Undogenites, having the rank of genera. 

 Under the second class, besides Galamites of Schlotheim, Syringoden- 

 dron of Sternberg, and other genera, there occur for the first time the 

 genera Sigillaria and Stigmaria. Sternberg's Lepidodendron is divided 

 into Sigillaria and Sagenaria, to the latter of which Sternberg's name, 

 Lepidodendron, is now generally preferred. Stigmaria is the equiva- 

 lent of Sternberg's Variolaria. Under the third class Lycopodites is 

 substituted for Schlotheim's Lycopodiolithes, Asterophyllites for his 

 Gasuarinites, and Phyllites for his Bibliolithes. Schlotheim's Filicites 

 and Poacites are adhered to and the new genera, Sphenophyllites and 

 Ficoides, are established. Under the fourth class Schlotheim's two 

 genera, Oarpolithes and AnthoUthes, are retained. 



^' C. F. Martius. De plantis nonnnllis antediluvianis ope specJiium inter tropicos 

 viventium illustrandis. Denkschr. der konigl. baieriscli. botan. Gesellsch. in Eegens- 

 burg, Band II, 1822, pp. 121-147, PI. I and II. 



2« M^moires du Museum d'bistoire naturelle, Paris, Tome VIII, 1822, pp. 209-210. 



