698 GEOLOGY OF THE YELLOWSTOXE NATIONAL PARK. 



Salix eloxgata ? ( ). Well. 

 Suli.r vlonijafa O. Web. Lesquereiix: Tert. FL, p. H!'.», PI. XXII, figs. 0, 7. 



A single quite well preserved specimen that seems to belong' to this 

 species. The nervation, however, is not' well preserved, but as nearly as 

 can be made out it may be referred to this form. 



Habitat: Fossil Forest, lower stratum, No. 1221 of Hague's Yellow- 

 stone National Park collection; collectec} by Arnold Hague, September 

 24, 18S4. 



BETILACE.E. 



BiCTULA IDDING.sl U. sp. 

 PL LXXXVI, figs. 4, 5. 



Leaves membranaceous, ovate, slig-htly unequal-sided, rather abruptly 

 roundel 1 to the base, more i)rolonged al)Ove; margin regularly toothed from 

 near the base, teeth slightly unequal, a little hooked; nervation pinnnte 

 anil craspedodrome; miilrib widl marked, .straight; seconchu-ies about 10 

 pairs, mainly alternate, occasionally opposite, arising at an angle of about 

 45°, straight or nearly so, terminating in the larger teeth, often with forks 

 near the margin, all of which enter the other teeth; nervilles obscure, l)ut 

 npparently percurrent and at right angles to the secondaries; iiner nerva- 

 tion not preserved. 



This species is represented by 3 very perfect leaves, all of which are 

 preserved on the same piece of matrix The most perfect one tigured is 

 8 cm. in length and 4.5 cm. wide, while the other is about 8 cm. long and 

 less than 4 cm. wide. The petiole belonging to this specimen is 7 nun. 

 in length. 



This species somewhat resendiles a number of described forms, as, for 

 exanqjle, Bdula stevensoni Lx.,^ from Carbon, Wyoming, from wdiich it differs 

 somewhat in shape, numbei- of ])airs of secondaries, and in the more regularly 

 serrate margin. Betiila elUptica Sap., as identified l)y Lesquereirx" from 

 John Day Valley, Oregon, is perhaps closer, yet this differs in having only 

 6 or 7 pairs of secondaries and also in the teeth. Bctiihi /Kirce-dentata 

 Lx., from the same locality, has the same kind of teeth, but differs in size. 



'Tert. Fl., p. 139, PI. XVIII, figs. 1-5. 

 -Cret. autl Ti-rt. Fl.,p. 242, PI. LI, tig. 6. 



