lg FOSSIL FLORA OF THE SIEREA NEVADA. 



Ficus tilieefolia, Al. Br. 

 PL IV. Figs. 8, 9. 



leaves large, sitbcoriaceous, entire, uneqailati nth intimately three or five nerved, ovate, 

 rounded or subcordate at the base, pointed or acuminati ; petiole thick. 



This species differs from the former by its thinner primary nerves, and 

 their divisions ascending nearly straight to the borders, where they ab- 

 ruptly curve in bows, often touching the margins ; by the distinctly unequi- 

 lateral base of the more narrowly pointed leaves, and the square primary 

 areolation. This species is well known, its characters definite, and its dis- 

 tribution very wide. The leaves greatly vary in size, Fig. 9 representing 

 its small forms, Fig. 8 the middle ones, for there are leaves of this spe- 

 cies twice as large. It has been described by European authors from 

 most of the stages of the Miocene. On this continent we find it already 

 in the lowest strata of the Eocene Lignitic, as at Point of Rocks, for 

 example, quite near the top of the Cretaceous measures. It abounds at 

 Golden, Colorado, Black Buttes, Wyoming, etc., and is therefore repre- 

 sented in the whole Tertiary. No species has been seen in the Creta- 

 ceous Dakota group, however, which could indicate any relation to it. 

 The type is represented at the present time by Ficus sgcomorus, Linn., an 

 analogous species. 



Habitat. — Chalk Bluffs, California. Voy's Collection. 



Ficus microphylla, sp. nov. 

 PI. IV. Figs. 10, 11. 



Leaves small, coriaceous, very entire, broadly oval or rhomboidal in outline, rounded 

 upwards to a short obtuse point, and downwards to a thick petiole ; palmately three- 

 nerved from tin slightly unequilateral base; nervation, camptodrome. 



The species is represented in the collection by three leaves, all about 

 of the same size, the largest three centimeters long, and a little more 

 than two centimeters broad. The nervation is of the same character as 

 that of the two former species ; but the primary nerves are very thin, 

 in three only, and on a more acute angle of divergence than that of 

 the secondary ones. The lateral nerves ascend to above the middle 

 of the leaves, where they curve near the borders, anastomosing by simple 

 flexure with the secondary veins, which are scarcely branched, merely 



