74 Later Extinct Floras of North America, 



Aristolochia cord i folia, (n. sp.) 



Leaves petioled, heart-shaped, pointed, entire ; nervation sparse, 

 midrib Btrong al base, vanishing above, basilar lateral nerves sup- 

 plying the lower halt' of leaf, much branched, upper laterals small, 

 branched, branches connecting. 



This leaf lias essentially the form and nervation of our living 

 species of Aristolochia, resembling most A, tomentosa. With- 

 out more material, it is impossible to say whether it is distinct 

 from that species or not, as the form of the leaves must vary 

 Bomewhat, and one specimen can hardly serve for making an 

 intelligent comparison. Waiting the collection of other ex- 

 amples of this plant, and not having satisfactory evidence of 

 identity, I have given it a distinctive name. 



Tin- -vims AristolocMa is represented in the Tertiary ami 

 probably in the Cretaceous rocks, but by species with which 

 this is not likely to he confounded. 



Formation and Locality. Lignite Tertiary beds. Banks of 

 Yellowstone River, (Dr. Hayden.) 



l'liyllilc* Cupanioides. (n. sp.) 



Leaves large, fleshy, ovate, elliptical in outline, rounded at base, 

 Bub-acute at summit, margins coarsely aud obtusely toothed above, 

 simple or waved below; nervation pinnate, strong ; midrib straight 

 or flexuous, lateral nerves, ab ml sis on each side, crowded below, 

 more remote above, basilar pair short and simple, uniting above 

 with the tertiary branches of the second pair to form a marginal 

 festoon, middle secondaries i ach bearing one or t wo branches near 

 the summits, upper one simple ; tertian nervation distinct, forming 

 lattice-like bars connecting the secondary nerves al right angle-. 



These fine leaves exhibit a resemblance in their texture and 

 crenate margins to those to which I have given the name 

 <d' Ph. carneoBus. They are, however, <<\' differonl form, 



and have a more simple and rectilinear nervation. The col- 



lecti fDr. Bayden contains a great number of fragments of 



iliir- sp< . but, up to the present time, 1 have failed to find 

 among living plan'- any which afford a satisfactory compari- 



