M. De CandoUe on Fossil Vegetables. 89 



portions of these few figures, it would appear, that the number 

 of Phanerogameae exceeds that of the Cryptogameae, which is 

 the opposite of what occurred in the earlier formations. 



The genera are exceedingly different from those in the coal 

 measures. It appears not one is common to the two formations, 

 and certainly no one species is so. All the plants are terrestrial. 



Fifth Epoch-Shell Limestone.—"' This formation," says 

 M. Brongniart, " which appears to be nearly wholly marine, 

 has hitherto supphed very few fragments of vegetables, and 

 these can be considered only as traces of the vegetation which 

 previously covered some portions of the land, and the greater 

 part of which was not buried until the formation of the arenace- 

 ous and clay beds which overly the limestone." The best cha- 

 racterized of these debris is a fern, and one of the Cycadeae, dis- 

 covered near LunevlUe by M. Gaillordat. There are also some 

 fuci. 



3. Third Period— Middle Deposit Series. 



Sixth Epoch — Keuper, Maries and Lias. — The predominance 

 of Cycadese is the characteristic trait of this epoch, for of twenty- 

 two species which have been recognised, they form the half. 

 No others of the dicotyledons have been found in it, and only 

 one monocotyledon and ten of the aetheogameas. No aquatic 

 plant has been found. 



Seventh Epoch — Jura formation. — M. Brongniart compre- 

 hends under this name the oolitic rocks of English geologists, 

 and some of the strata that separate them from chalk, as for 

 example, the ferruginous sands and sandstones of the forest of 

 Tilgate. The greensand, however, is excluded. 



The Jura district furnished only one species of the enumera- 

 tion of 1828; the greater number was supplied from Whitby, 

 Portland, and Stonesfield in England. 



Of fifty-one species enumerated by M. Brongniart in 1828, 

 and obtained from a great number of geologists, three species 

 were marine. 



The number of Cycadeae is very remarkable. There arc 

 seventeen of them, eleven of which belong to the genus Zamia ; 



