710 GEOLOGY OF THE YELLOWSTONE NATIONAL PARK. 



apparently rather abruptly pointed. The teeth are strong and sharp-pointed, 

 with rounded sinuses. 



This species seems to be allied to Q. boweniana Lx., 1 from California, but 

 differs essentially in having much larger, sharper teeth and straight 

 secondaries. It is also allied to Q. yanceyi which has undulate or slightly 

 toothed margin and fewer, more curved secondaries. It somewhat 

 resembles a leaf that has been described as Hicoria eidveri, which, however, 

 differs in the teeth, and in having a camptodrome instead of a craspedodrome 

 nervation. 



Habitat: Yellowstone River, one-half mile below mouth of Elk Creek, 

 at top of bluff; collected by F. H. Knowlton, August, 1888. 



Dryopyllum longipetiolatuji n. sp. 

 PL LXNXVII1, tigs. 6, 7. 



Leaves lanceolate, long wedge-shaped at base, long narrowly acuminate 

 at apex, margin regularly undulate-toothed, the teeth sharp, upward point- 

 ing, separated by rather shallow sinuses ; petiole very long, slender ; midrib 

 thick, straight; secondaries numerous, alternate, 12 pairs or more, at a low 

 angle in the lower part, more acute above, slightly curving outward in 

 passing to the margin, all ending in the teeth ; nervilles at right angles to 

 the secondaries, obscure but apparently mainly percurrent ; finer nervation 

 destroyed. 



This species is represented by a number of specimens, none of which 

 are complete in a single example, but by combining several a good idea of 

 the species is given. The length appears to have been about 20 cm. and 

 the width in the middle 4 cm. The petiole is long, being 2.5 cm., and pos- 

 sibly not all preserved. In the larger leaves the secondai'ies are quite 

 remote and distinctly alternate. They arch slightly in passing to the teeth. 



The leaves of this species were at first confounded with leaves of 

 Castanea pulchella, with which they occur in the same beds, but they differ 

 in the longer petiole, the smaller teeth, and in the irregular, arching 

 secondaries, with an occasional intermediate secondary between. The 

 teeth of the upper third of the leaf are also of a different character. 



' Mem. Mus. Comp. Zool., Vol. VI, No. 2, p. 6, PI. II, figs. 5, 6. 



