FLORA OP THE GREEN RIVER GROUP. 145 



DICOTYLEDONES. 



MYRICACE^. 



MYRICA. 



•'II. S. Geol. Rep.," Tii, p. 12G. 



§ 1. Leaves dentate, serrate or uudulate. 



Myrica Copeana, Lesqx. 

 IbUL, p. 131, pi. xvii, tig. 5. 



Myrii-a obscura, 6p. nov. 

 Plate XXXII, Figs. 8-10. 



Leaves linear-lanceolate, coarsely serrate, rounded in narrowing to the petiole, 

 uiiequilateral at base; nervation obsolete. 



This form is related by its shape and the teetii ot the Jjorders to 31. 

 BankcicefoUa, Ung., as figured by Heer, ''Fl. Tert. Helv.,"' pL c, ligs. 3-10, 

 (Uffering merely by the more rounded and unequilateral base of the leaves 

 and the total disappearance of lateral nerves ])y immersion into a thick 

 carbonaceous coating. However, fig 6 of Heer represents two leaves 

 without traces of lateral nerves, and fig. 8 has the base somewhat rounded 

 and unequilateral, though not quite as distinctly as in the American form. 

 The pedicel of this last figure is also slender, of the same length as in fig. 

 10 of our plate. The leaves are on an average a little smaller than those 

 of M. BankskvfoUa, 7 to 9 centimeters long and 1 to 2i centimeters broad 

 above the base; the teeth are generally sharp, slightly inclined upward. 



//«i.— Florissant. U. S. Geol. Expl. Dr. F. V. Hayden. 



Myrica Liudwigii, Schp. 



"U. S. Geol. Bep.," vii, p. 133, pi. Ixv, fig. 9. 



3Iyrica acuiuinata, Ung'. 



lUd., p. 130, pi. xvii, fige. 1-4. 



Myrica rigida, sp. nov. 



Plate XXV, Figs. 3, 4. 



Leaves thick, rigid, snbcoriaceous, lanceolate-acuminate, serrate, rounded and 

 unequilateral at base, short petioled; medial nerve thin, straight, the lateral crasped- 

 odrome. 



This species differs from the preceding by the distinctly lanceolate 

 form of the leaves equally and gradually narrowing from the rounded 

 base to the apex, by the short petiole, the distinct lateral veins and the 



OF 10 



