FLORA OF THE GREEN RIVER GROUP. 149 



these leaves with the more or less broadly cuneate base decurrent to the 

 short petiole, their sharply dentate lobes, the membranaceous substance, 

 the nervation, I am not able to find any difference to separate them into two 

 or more species, and still less to refer them to a different genus. Some of 

 the leaves (fig. 14 especially) have some of the characters of Crataegus, but 

 the nervation recalls them to Myrica. The small seed, fig. 15, though a 

 seed of Myrica, is not positively referable to this species. 

 Hah— Florissant. U. S. Geol. Expl. Dr. F. V. Hayden. 



Myrica latiloba, Heer, var. acutiloba. 

 " U. S. Geol. Kep.," vii, p. 134, pi. xvii, fig. 13. 



§3. Leaves pinnately lobed ( Gomptonia). 



The leaf mentioned with the description of this species as being identi- 

 cal in character with it and obtained from the Miocene of Oregon is figured, 

 pi. 1. fig. 10, and described with Miocene plants. 



Myrica Brongniarti?, Ett. 



"U. S. Geol. Rep," vii, p. 135, pi. xvii, fig. 15. 



Myrica Alkalina, sp nov. 



Plate XLVa, Figs. 10-15. 



Leaves short, trilobate and obtusely dentate from a cuneate base, or lauceolate, 

 rounded and narrowed to tbe base, pinnately, obtusely or acutely dentate. 



The species represented by a large number of fragmentary leaves, 

 mixed upon the same specimens, present two forms, rather marked vari- 

 eties, especially differing by acute or obtuse lobes or teeth. The leaves 

 are subcoriaceous or membranaceous, somewhat large, 3 to 8 centimeters 

 long. 2* to 3 centimeters broad, either lobate with narrow cuneate base, 

 or pinnately deeply dentate, more or less obtusely cuneate at base. The 

 medial nerve is thick; the lateral nerves, at a broad angle of divergence, 

 much curved in passing up to the points of the lobes, are generally sepa- 

 rated by parallel shorter tertiary veins, anastomosing with oblique nervilles 

 or branchlets derived from the secondary nerves. 



The species is comparable to both Myrica Vindobonensis, Ett., in Heer, 

 " Fl. Tert. Helv.," p. 34, pi. lxx, figs. 5, 6, and M. Ungeri, Heer, I. c, p. 35, 

 pi. lxx. figs. 7, 8, differing from both by shorter comparatively broader 

 leaves, more equally dentate-lobed. 



