694 GEOLOGY OF TUE YELLOWriTOiNE XATIO^'AL FAEK. 



SALKACEyE. 



PoPULUs OLANDULiFEKA Heer. 

 n. Lxxxiv, tig. 1. 



I'tipiiJiis i/htnditlij'rra Heer. Les(iuereux : Oret. and Tert. Fl., p. 226, I'l. XLVIa, tigs. 

 3, 4. Ward: Types of the Laramie FL, i). 19, PL IV, figs. 1-4. 



The collection contains 3 specimens with A'ery line ronnded or sharp 

 teeth, that are referred witlKUit hesitation to this species, as fiiinred liy 

 Lesqnereux and Ward, t'rnni the typical Fort Union j^rou]) of the lower 

 Yellowstone. The best of these is fig-nred. 



Habitat: Yellowstone Kiver, one-half mile Ix'hnv the month of Elk 

 Creek; collected Ijy F. H. Knowlton, Au-iist, 1S88. 



Popi'LT's si'ECiosA Ward. 



I'L LXXXIV, tig. A. 



FojtulK.s ■s2)ivi().'<ii Ward: Types ot' tlie Laramie FL, p. 21), PL V, tigs. 4-7. 



The Park c(dlection contains sometliing over 50 specimens that are 

 referred to this species. Tliev are very perfectly jireserved, and the petiole 

 is in some cases 8 cm. in length. There can l)e no (jnestion as to their 

 correct reference to the Fort Union species. 1 shonld also iiudine to refer 

 to this species certain of the leaves described as Po2)iiIiis (iiiihli/)-l///iirha'WnYd 

 and P. oxyrJii/ucIid AVard, from the same beds. The very slight differences 

 separating these forms seem hardly to be worthy of specific rank. 



Habitat: Yellowstone Kiver, one-half mile below month of Elk 

 Creek; collected l^y F. H. Knowlton, Angust, 1888. 



Poi'ULUs ZADDACHi Hecr. 



Po2>i(liis zaddticlii Heer: FL Tert. Helv., Vol. Ill, p. .^OT. Lesiiuereax: Cret. and 

 Tert. FL, p. 158, I'L XXXI, tig. S. 



A few specimens were obtaiiieil tliat nnist be referred to this species. 

 Habitat: Late acid lireccia, P^•l■amid Peak; collected by Arnold 

 Hague, 18i)7. 



