l.M UNITED STATES GEOLOGICAL SURVEY— TERTIARY FLORA. 



L., of North America. The fragment indicates a leaf membranaceous or 

 rather subcoriaceous. 



Habitat. — Green River gruiip, near t-he mouth of White River, Utah 



{Prof. W. Denton). 



§ 2. — Leaves pinnaieh/ lohed. 



COMPTONIA. 

 niyrica latiloba, Heer, var. aciitiloba. 



Plate XVII, Fig. 13. 



Myrioa latiloba, Heer, Flor. Tert. Helv., iii, p. 176, pi. cl, figs. 12-15. 

 Myrica latiloba, var. acutiloba, Leaqx., Annual Report, 1873, p. 412. 



Leaf membranaceoiis, oblong-lauceolate, cuueate at the base to a comparatively long slender 

 petiole, pinnately divided in short angular acute lobes; secondary veins distinct, open, mixed. 



This leaf has from the base to the middle, where it is broken, the same 

 character as those described by Heer, it being apparently short, abruptly 

 narrowed to the point. As the nervation is of the same character, the lower 

 secondary veins very open, caraptodrome, the upper ones at a more acute 

 angle of divergence and entering the teeth or craspedodrome, and interme- 

 diate, short, very thin; secondary veins, soon dissolved into the reticulation, 

 there is no appreciable difference but the acute lobes. Even this may be 

 casual and unimportant, for in figs. 12 and 13 of Heer {loc. cit.), the lowest 

 lobes are mere acute teeth, and, in our figure, the upper ones are apparently 

 obtuse, though very short. I am the more inclined to consider this leaf as a 

 mere variety of the European species, that I have from the Miocene of 

 Oregon, John Day Valley, near Bridge Creek, a specimen of a leaf preserved 

 in its integrity, and exactly concording in all its characters, even the size, with 

 Heer's species. 



Habitat. — Florissant, near Middle Park, Colorado (Dr. F. V. Hayden). 



IWyrica parti ta, Lesqz. 



Plate XVII, Fig. 14. 



Myrica partita, Lcsqx., Annual Report, 1873, p. 413. 



Leaves subcoriaceous, narrow, linear, alternately equally divided to the middle nerve into equal, 

 broadly lanceolate, acuminate lobes, slightly denticulate on the lower borders ; secondary veins three in 

 each lobe, parallel, the upper one longer, passing up to the point of the lobes, the lower ones to the teeth. 



A mere fragment, too small to indicate satisfactorily the characters of 

 the leaf It is comparable to the species of Myrica whose type is M. O^niti- 

 gensis, Al. Br., which are common in the Miocene of Europe But for the 

 small dcnticulation of tiie borders, it would be identical with M. incisa,ljndw. 

 (Paleont., viii, p. 9o, pi. xxx, figs. 7-15). This ditlerence is an important 



