72 UNITED STATES GEOLOGICAL SURVEY— TERTIARY FLORA. 



structure to species of this family. Fossilized trunks of Conifers have 

 been found also in the Subcarboniferous of England. In the true North 

 American Carboniferous, we have as yet scarcely any trace of Conifers ; at 

 least, the remains referred to them, those of the genus Arfisia, for example, 

 are still of uncertain relation. If the Cordaites of the coal have apparently 

 characters which relate them to Cycadece, the species of Noeggeratkia, of 

 the same formation, might as legitimately be referred to Conifers. This ques- 

 tion is still in a state of uncertainty. Immediately above the Coal-Measures, 

 even in tlieir higher strata, and in the Lower Permian, the Conifers appear 

 in a fair proportion by two new genera, Walchia and Volzia, which persist 

 into the Trias, with a few Cypressinece. The Jurassic has genera of the 

 Araucarice, the Ahietinea:, and the TaxodicE essentially predominant, as in the 

 Cretaceous also. But the larges.t number of Conifers is known in the Ter- 

 tiary, wherefrom two bundled and twenty-five species or more are described 

 until now. This does not positively indicate what may be the distribution in 

 the other formations, whose flora, comparatively to that of the Tertiary, is 

 scarcely known, except that of the Carboniferous, however, from which four- 

 teen species of Conifers are described in Europe from fossilized wood. Of the 

 genera still present in the flora of our epoch, Arnucaria appears in the Trias, 

 is more abundant in the Jurassic, and absent from the flora of the Miocene, 

 now ^inhabits the countries south of the equator, especially New Holland. 

 Sequoia, Cretaceous and Miocene, is left in the present flora by the two well- 

 known species of California, S. semiyervii-ens and S. gigantea. Finns, with a 

 few representatives in the Cretaceous, becomes extremely predominant in the 

 Miocene, from which more than one hundred species are described ; while 

 Larix, Cedrus, Abies, and Taxodium, which appear at first in the Tertiary, 

 continue to the present time. 



CUPRESSINE^. 



WIDDRINGTONIA, EndL 

 Widdrins^^tonia! coniplanata, Lesqz. 



Plate LXII, Figs. 13, 14. 



Widdringtonia complanata, Leaqx., Aunaal Report, 1874, p. 299. 



Stem thick, disticho-pinnato; braucblets short, thick, obtuse, alternate, obliiiue; leaveB small, 

 apparently in spiral order, closely imbricate and appressed, oblong, lingulate-pointed upon the primary 

 branches, ovate-pointed or rhomboidal and short upon the brauchlcts. 



■ This species appears to have been of a soft though thickish substance. 

 All the specimens are flattened, even the branches, and, in that way, the form 



