EXTENT OF FOSSIL AND KECENT CYCADE.1l. 491 
M. Ad. Brongiiiart eniunerates about seventy 
species of land plants in the Secondary forma- 
tions, (from the Keuper to the Chalk inclusive ;) 
one half of these are Coniferae and Cvcadeae, 
and of this half, twenty-nine are Cycadeae ; the 
remaining half are chiefly vascular Cryptoga- 
mise, viz. Ferns, Equisetacese, and Lycopodia- 
ceae. In our actual vegetation, Coniferae and 
Cycadeae scarcely compose a three hundredth 
part.* 
The family of Cycadeae comprehends only two 
living Genera ; viz. Cycas, (PI. 58.) and Zamia. 
(PL 59.) There are five known living Species of 
Cycas and about seventeen of Zamia. Not a 
single species of the Cycadeae grows at the present 
time in Europe ; their principal localities are 
parts of equinoctial America, the West Indies, 
the Cape of Good Hope, Madagascar, India, 
the Molucca Islands, Japan, China, and New 
Holland. 
Four or five genera, and twenty-nine species of 
Cycadeae, occur in the fossil Flora of the Secon- 
dary period, but remains of this family are very 
* The fossil veg:etables in the Secondary series, although they 
present many kinds of Lignite, very rarely form beds of valuable 
Coal. The imperfect coal of the Cleveland Moorlands near 
Whitby, and of Brora in Sutherland, belong to the inferior re- 
gion of the Oolite formation. So also does the bituminous coal 
of Blickeber^ near Minden, in Westphalia. 
The coal of Hoer in Scania is either in the Wealden formation, 
or in the Green-sand {A?m. des Sciences Nat. torn. iv. p. 200). 
