740 GEOLOGY OF THE YELLOWSTONE NATIONAL PARK. 



KHAMNACE.E. 



Rhamnus rectinervis Heer. 



BJianmus rectinerris Heer: Fl. Tert. Helv., VoL III, p. SO, PI. OXXY, figs. 2, 0. Les- 

 quereux: Tert. Fl., p. 279, PI. LII, figs. 12-15. 



Tliis 8i)ecies ^Yas first detected in the Park by Lesquereux,' and the 

 present collection contains a number of specimens that may be similarly 

 referreil. They are all entire, in which respect they resemble fig. 14 of 

 Lesqiiereux's plate (loc. cit.). 



Habitat: Fossil Foi'est Ridge, bed No. 3, ":\Iagnolia bed;" bed No. 7, 

 "Castanea bed;" collected by Ward and Knowlton, August, 1887. 



Paliurus colombi Heer. 

 PI. CI, fig. 7. 

 raliiinis colombi Heer. Lesquereux: Tert. Fl., p. 273, PI. L, figs. 1:3-17 (1878). 



The little specimen figured ajjpeai's to lie tlie only one obtained in the 

 area under discussion. It is of the same size and shape as many of the 

 figures of this species, but seems to differ slightly in having 2 strong sec- 

 ondaries on one side of the nndrib. It, howe^'er, approaches certain of the 

 figures given by Heer'- of arctic examples of this species. 



Habitat: Head of Tower Creek; collected by W. II. Weed, Septem- 

 ber 25, 18S.5. 



ZiZYPHUs SERRULATA Ward. 



PI. (JI, figs. 4, 5. 



Zizijphm scrndiiia \Y;ud: Types of tlie Laramie Fl., p. 73, PI. XXXIII, figs. 3, 4 



(1887). 



The two figured examples agree very closely with the figures given by 

 Professor Ward. The}' l)oth have teeth well marked, and t)ms agree with 

 fig. 4 (loc. cit.). They are not quite so well preserved as the types, and do 

 not show the finer nervation, l)ut there can be no doubt as to their identity. 



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

 Creek, top of bluft'; collected by F. H. Knowlton, August, 1888. 



' Haydeu's Ami. Rept., 1878, Pt. II, p. 49. 

 ' Fl. Fos8 Arct., Vol. I, Fl. XIX, tig. 3. 



