370 



entire, though somewhat lacerated, about two and a half centimeters 

 long, including" the petiole (three millimeters), and one and a half 

 centimeters broad, oblong or Ungulate, with borders cut from the base 

 in comparatively large, pointed teeth, either simple or with small XDro- 

 tuberances on the back of the largest ones ; nervation craspedodrome, 

 the secondary veins entering the large teeth, and more or less irregu- 

 larly and obscurely dividing in very thin branches, joined in the middle, 

 and forming a large, scarcely distinct areolation. By the form of the 

 leaves and the border-divisions, this species is comparable and closely 

 related to Rhus Pyrrhw, Ung., as figured in Tert. Flor. Helv. of Heer 

 (PI. CXXVI, fig. 20), which has leaves, round truncate at the base, and 

 short-petioled, as in one of our specimens. Like Bhus PyrrJiw, it is also 

 comparable to Ehus aromatica, Ait., a very common species of our pres- 

 ent flora. This has also generally doubly dentate teeth, and, in southern 

 specimens, a thickish, membranaceous consistence. 

 Habitat. — Point of Eocks, Dr. F. V. Hayden. 



18. JUGLANS RHAMNOTDES, Lsqx. 



A smallleaf of this species, which is not yet, however, definitively lim- 

 ited, as seen from the description in Dr. F. V. Hayden'sEeport for 1871 

 (p. 294), and which may be identical with Jvglans Leconteana, Lsqx., and 

 Cornus acuminata., Newby. Though it may be of the value of the species, 

 the leaf from Point of Eocks is identical in all its characters, even 

 in its size, with some of those found in the burned beds of red shales at 

 Black Butte. 



Habitat. — Point of Eocks, Br. F. V. Ilayden. 



19. PopuLUS MELANAEiA, Heer. 



Leaves with along, slender petiole; deltoid, subtruncate at base; 

 borders acutely serrate; primary basilar lateral nerves emerging from 

 above the border- base of the leaf, with a pair of thin marginal veinlets 

 underneath. 



Considering what can be' seen of this leaf from the fragment which 

 represents merely its lower half, with the long, slender petiole, the 

 distinct nervation, and a few of the border-teeth, it exhibits characters 

 in accordance with those described above, and translated from Schim- 

 per's Vegetable Paleontology, and especially with the figure given of this 

 species in Plor. Tert. Helv. (PI. LIV, fig. 7). Professor Heer remarks, 

 that it essentially differs from Poptdus latior, var. stihtruncata, by the 

 IDOsition of the lateral ])rimary nerves at a distance from the border-base 

 of the leaves. In the leaf figured as indicated above, this distance is 

 still greater than in that of the Flor. Helv. Heer remarks also that 

 he has seen a large number of specimens of the same species, but that 

 in all exceiJt one, Avhich he has figured, the upper j)art of the leaves 

 was destroyed, as it is in ours. He mentions as distinctive characters, 

 the acutel}^ serrate borders of the leaves, and the middle nerve thicker 

 than the lateral ones, the same as seen upon our specimen. . I have, 

 therefore, no doubt about the relation of this leaf to the European 

 species. 



Habitat. — Point of Eocks, Dr. F. V. Ilayden, 



20. QuERCUS competens, sp. nov. 



Leaf oval, equally narrowed to the obtuse point and to the base, 

 irregularly and obtusely dentate ; secondary* veins distant, parallel, at 

 an acute angle of divergence. 



This leaf, unsatisfactorily preserved, is comparable to many species of 



