238 UNITED STATES GEOLOGICAL SURVEY— TEKTIAEY FLOltA. 



Habitat. — Mount Brosse, Colorado; leaves with entire lobes ( W. Mitchell). 

 Elk Creek, near Yellowstone River, Montana {F. C. Sloane, Jos. Savage). 

 Evanston, Wyoming (Prof. F. B. Meek). Yellow Creek and Mount Brosse, 

 Colorado, with Cissus lohato-crenata, Laurus Brossiana, etc. {Dr. F. V. Hai/den). 

 Not seen at Golden, Colorado, nor at Black Buttes, Wyoming. It appears to 

 be a northern species, or, at least, widely distributed in the North Lignitic, 



AMPELIDE^. 



In this order, I should perhaps consider merely the North American 

 genera Vitls and Ampelopsis, the two species of Cissus of the present flora 

 being generally described as Vilis; and, indeed, both these genera are united 

 in one by the highest authorities. We have, however, some fossil leaves 

 identical with fossil species described as Cissus by the European paleontolo- 

 gists, and thus have to follow the distinction which they have established. 

 The Cissus species of the present flora are mostly of the tropical and equa- 

 torial regions, especially of India, South America, and the Southern Islands. 

 Per contra, the genus Vitis, in its limitation, has the greatest number of its 

 living representatives in the United States, which, without counting two 

 of Cissus, has eight species of Vids. One inhabits South America; Asia has 

 seven, and Japan two. The origin of the Grape, so widely cultivated in 

 Europe, is apparently unknown. From the historical records of its use, 

 it ought to be placed in Asia. Anyhow, we find the two genera Cissus and 

 Vitis represented in the European Tertiary, the first by fifteen species, two 

 of which are Eocene, and the second by eleven, which all are Miocene. In 

 this country, we may, it seems, refer the origin of the group to the Creta- 

 ceous, for t'rof Heer, in his Phyllites du Nebraska, has described as Cissites 

 a leaf which he considers as more distinctly representing a species of the 

 Ampelidece than that of any other family of plants; and, from the same for- 

 mation of the Dakota group, I have referred to the same order nine species, 

 following, for this determination, the opinion of Count Saporta. Aud as we 

 have, in the Lower Lignitic Eocene, leaves and seeds evidently representing 

 Cissus and Vitis, this old origin is thus apparently confirmed. 



Cissus laevigata, Lesqz. 



Plate XL, Figa. 12, 13. 



Citsus l<Bviga(a, Lesqx., Annual Report, 1872, p. 380.— Schp., V^g€t. Pal., iii, p. 602. 



Leaves membranaceous, with a Binooth or polished surface, broadly oval in outline, narrowed in 

 a round curve to the petiole ; borders entire. 



The two leaves representing this species have the upper part destroyed. 



