94 UNITED STATES GEOLOGICAL SURVEY— TERTIARY FLORA. 



seen until now in the Green River group, and none in the Pliocene of Cali- 

 fornia. 



This seems a distribution in a contrary direction to that observed for 

 Europe. It is, however, very probable that, as the leaves of Smilax have 

 been found at two different stages of the Lignitic, and as even the type seems 

 to be represented already in the Cretaceous of Nebraska by vegetable remains 

 referable to the DioscorecB, the researches in the still unknown field of the 

 North American flora will fill the gaps by new discoveries. 



SMILAX, Toum. 

 Smilax grandiToIia, Ung. 



Plate rX, Fig. 5. 



5»nt7ai grandifoUa, Heer, Fl. Tert. Helv., p. 82, pi. xxx, fig. 8.— Ett., Fl. v. Bil., p. 28, pi. vi, figs. 15, 

 16.— Ung., Syll. PI. Foss., p. 7, pi. ii,fig8. 5-8.— Lesqs., Annual Reports, 1872, p. 385; 1873, p. 

 395. 



Smiladtes grandifoUa, Ung., Cblor. Protog., p. 129, pi. xl, fig. 3. 



Leaves brciilly ovate, cordate at the base, gradually acuminate, seven-nerved, the two outside 

 nerves ascending to the middle, the inside ones passing uj) in a curve to near the point; veinlets distant, 

 oblique. 



This leaf, about seven centimeters long (point broken), five and a half 

 centimeters broad toward the base, where it is enlarged, cordate at base, 

 curving and narrowing upward and apparently acuminate, is in all its charac- 

 ters of form and nervation identical with that in fig. 6 of Unger {loc. cit). It 

 merely differs by its smaller size, a character of no moment in leaves of this 

 kind. The secondary veins are slightly more oblique to the middle nerve. 

 This species is not rare in the Miocene of Europe; it has been described 

 after Unger, by Heer, d'Ettingshausen, Weber, and represented by leaves of 

 a shape and nervation more different from the typical form than ours, for the 

 species varies much in the size and form of its leaves, some being as broad as 

 ten centimeters, some merely rounded, not cordate, to the base. To this last 

 variety may be referable a leaf described in Annual Report, 1873, p. 395, whose 

 lower half only is preserved, round, not cordate, abnormally five-nerved by 

 the division near the base of one of the lateral veins on one side, and on the 

 other by a marginal veinlet from the top of the petiole; the nervilles are less 

 oblique to the middle nerve than in the leaf which we have figured. The 

 essential difference of this fragment, too incomplete for representation, is the 

 round base of the leaf and its small size, of the same size as that of fig. 8 of 

 Unger (loc. cit). 



