LESQUEEEL-x.] PALEONTOLOGY LIGNITIC FLORA — SPECIES. 411 



I*opuLUS EiCHAKDSONi, Heer. 



Leaves pelioled, broadly ovate or'nearly round, ta"imcate at tbe base, 

 deeply obtusely creuate, 5-uerved from tbe base; primary nerves flexu- 

 ous, branching in right angle or at a broad angle of divergence; sub- 

 stance thin or not coriaceous. Of the six specimens representing leaves 

 of this species, none is preserved in its whole. Though fragmentary, 

 however, enough is left to recognize the essential characters and identify 

 the species. Tbe leaves are variable in size, from 4 to 8 centimeters in 

 diameter, some narrower, more elongated, ovate truncate or slightly 

 emargiuate to the petiole. From P. arciica, it differs essentially by tbe 

 thinner substance of the leaves, and by the deeply-crenate borders. 

 Some of tbe obtuse teeth are longer and narrower than represented in 

 the figures of this species, (Fl. Arct., p. 98, Tab. iv, vi.) 



Habitat. — Elko, Frof. Cope. 



Salix media, A1. Br. 



Tbe species already described from Green River specimens, (in Sup- 

 plement to Eeport for 1871 ) is represented still by two others, which, 

 also, have not preserved any trace of nervation, and are identifiable 

 only by the form of their leaves. 



SabitaL— Elko, Frof. Cope. 



Myeica Copiana, sp. nov. 



Leaf lanceolate, taper-pointed, 10 to 11 centimeters long, 3 centimeters 

 broad, doubly and deei)ly serrate, with alternate longer and shorter 

 acute teeth, penninerve; nervation craspedodrome ; secondary veins 

 open or nearly in right angle to the middle nerve, passing up to the 

 point of the larger teeth, with thinner, shorter tertiary veins between 

 them, ascending to tbe i)oint of the shorter teeth ; all curving slightly 

 upward in entering the teeth. This fine species, represented as yet by 

 a single specimen, is distantly related to Myrica Graeffii, Heer, (Fl. 

 Tert. Helv., Ill, p. 170, PI. cl. Figs. 19, 20;) tbe leaf of the Amer- 

 ican species being, however, twice as large, the teeth turned outside, 

 sharp, pointed, &c. The same specimen bears some alate seeds of a 

 coniier, like those described by Heer in Spitz. Fl. as Finns abies. 



Habitat. — Near Florisant, South Park, Frof. Cope. 



Myeica acuminata, Ung. 



Leaves coriaceous, with smooth surface, linear-lanceolate-acuminate, 

 dentate; nervation camptodrome, obsolete. These leaves, compared to 

 Unger's species as figured in Fl. of Sotzka, (PL vi, Figs. 5-10,) appears, 

 indeed, identical with it. But tbe author says of bis species, (p. 30,) ser- 

 raturis eqnalibus, minimis, approximatis, a character which is in dis- 

 accord with tbe figures {loc. cit.) and with that of our specimens. 

 This character, however, is of little importance in regard to identifica- 

 tion ; for one of our specimens, representing a long, acuminate leaf, has 

 equally serrate border on one side, while on tbe other the teeth are 

 close and unequal. As far as it can be seen, tbe secondary veins appear 

 close, straight to the point of tbe teeth, and on an acute angle of diver- 

 gence Irom the middle nerve. From another locality a set of specimens 

 represent the same species under the same form and nervation, but with 

 much smaller, narrower, and shorter leaves than those figured by Lnger, 

 and also than the first ones described above. 



Habitat. — Middle Park, Dr. Hayden, one mile west of Florissant, South 

 Park, l)r. Feale. 



