FLOKA OF THE GREEN RIVER GROUP. 161 



Ulmus Braunii, Heer. 



Phite XXVII, FigB. 1-4.8. 



Heer, "Fl. Tert. Helv.," ii, p. 59, pi. Ixxix, figs. 14-21; iii, p. 181, pi. cli, fig. 31; Gaud., "Contrib.," ii, p. 47, 

 pi. iii, figs. 3-9; Ludw., '^Palieoiitog.," viii, p. 105, pi. xxxviu, figs. 5-8; Ett., "Fl. v. Bil.."p. 64, 

 pi. xviii, figs. '23-26 



Leaves short-petioled, vesy uuequilateial, roniul or cordate at base, elliptical or 

 ovate-lauceolate, acute or acuminate, doubly or simply coarsely dentate ; teeth conical, 

 turned up; lateral veins open, at right angles toward the base, l-'-lS pairs; fruit peti- 

 elate, broadly-winged; wings lateral. 



This species is very variable in the form of the leaves and the more 

 or less acute teeth of the borders. The leaves, 4i to 12 centimeters long, 

 24 to 44 centimeters broad, are comparatively broader and shorter and 

 more unequilateral and difform than those of the preceding species. It is 

 very common in the European Miocene and is also abundantly found at 

 Florissant, where the fruits also are not rare. But these fruits, always 

 found ripe, do not agree with the figures given by Heer, loc. cif.. pi. cli, 

 fig. 31 : they are rather like those of U. Broxvnii, or U. longifoUa, Ung., as 

 figured in "Bil. FL," pi. xviii, figs. 4, 5, 8. The specific relation of the 

 seeds of Ulmus described by European authors is hypothetical, as well as 

 that of those I have figured. 



i^<5._Florissanf. Not rare; especially in Princeton Collection. 



PLANERA, Gmel. 



"U. S. Geol. Rep.." vii, p 189. 



Planera longifolia, Lesqx. 



Plate XXIX, Figs. 1-13 ; XLIV, Fig. 10. 



Leeqx., "U. S. Geol. Rep.," Tii, p. 189, pi. xxvii, figs. 4-6. 



Planera longifolia, var. myricsefolia. 



Plate XXIX, Figs. 15-27. 



From a comparison made in the examination of more than two thou- 

 sand specimens, representing not merely the leaves figured but a large 

 number of intermediate forms, I have been forced to admit that they all 

 belong to the same species, and that though some of them are closely allied 

 to the European Planera XJngeri, they constitute a different species. First 

 examining the relation of all the leaves from No. 1, the normal type, to 



C F 11 



