82 



Popidites salisburiafolia, Lesqx., American Journal of Science and Arts, loc. 



cit., p. 94. 



Leaves of small size, three-lobate, with very obtuse, half-round lobes, 

 either perfectly entire or rarely undulately-dentate, narrowed in a broad 

 angle of divergence to the petiole, which is slender and very long ; secondary 

 veins thin, subcraspedodrome, areolation formed of large, irregular quadrate 

 meshes. 



The reference of these leaves to Sassafras is very uncertain. Their 

 appearance is quite different, rather resembling leaves of some of those Am- 

 pelidece, Cissus, &c, which have a number of representatives in the Eocene 

 of the Rocky Mountains, though of a far different type, and to which Heer 

 refers one of his leaves of the Cretaceous of Moletin, under the generic name 

 of Ckondrophyllum. These leaves are of a thin texture ; the form and nerva- 

 tion, though analogous, differ also, especially by the apparently craspedodrome 

 character of the secondary veins, which, though the borders are perfectly 

 entire, do not seem to curve as in Sassafras ; the slender petiole is also com- 

 paratively longer than in any of the leaves of this genus. The leaf (Fig. 2) 

 was doubtfully referred to the genus Popidites on account of the craspedo- 

 drome character of the secondary nerves, and also of the thinness of the leaves. 

 It was at the time the only leaf of this type. I have since found many speci- 

 mens representing the same forms as in Figs. 3-4. They are apparently all 

 referable to the same species, the essential difference being only in the narrow 

 sinuses separating the more undulate lobes of the leaf in Fig. 2. The curving 

 of the broken petiole is evidently casual. The last specimen comes, however, 

 from a different locality, and the identity of these leaves may be ascertained 

 only by the discovery of intermediate forms. 



Habitat. — Lancaster County, Nebraska, Hayden, the specimen, Fig. 2 ; 

 all the other specimens from Salina Valley. 



Sassafras (?) subintegrifolium, Lesqx , PI. iii, Fig. 5. 



Leaf tkickish, broadly obovate, cmarginate at tbe rounded top, narrowed to a thick petiole, anorm- 

 ally tri-palmately nerved ; lateral veins at a distance above tbe borders, disjointed. 



Sassafras subintegrifolium, Lesqx., American Journal of Science and Arts, loc. 

 cit., p. 99 



By its general appearance, its thick, primary nerves, the narrowing of 

 the border to the base, this leaf seems referable to this genus. Even in 

 considering the primary nervation, we may recognize in the two lowest lateral 



