FLORA OF THE DAKOTA GROUP. 45 



LIQUIDAMBAR, Linn. 



1. 1 <i n id a in ba i- integrifolium, Lesqx. 

 Plate XIV, Fig. 3. 

 "U. S. Geol. Rep.," vi, p. 56, pi. ii, figs. 1, 3; xxiv, fig. 2. 



There is a degree of uncertainty in regard to the relation of the leaves 

 described under this name, as I have remarked it in the "U. S. Geol. Rep.," 

 I. c. If on one side they are related by their forms, especially the entire 

 margin, to species of Aralia, or perhaps more of Sterculia, their nervation 

 has more analogy to that of Liquidambar than to any other of the groups 

 to which they have been compared. Two well-preserved specimens of the 

 Museum of Comp. Zool., Cambridge, show the secondary veins somewhat 

 variable in distance and divergence, moderately curving to quite near the 

 borders, where they abruptly bend, following upward to the point where 

 they anastomose in simple festoons. They are separated by short tertiary 

 veins parallel to the secondary ones, dividing in the middle of the areas 

 in joining the borders at right angles as nervilles. I have not observed 

 this character in any of the fossil leaves which I have described as Aralia, 

 nor do I find it in the few living species which I have for comparison. 

 Another point of relation is remarked in the sub-cordate base of the leaves 

 of the cretaceous species which, like Liquidambar Styraciflua and the com- 

 mon Miocene species L. Europceum, have the lower lateral lobes either 

 curved back or at right angles to the petiole, so that the base of the leaf 

 is never cuneate. 



MORE^E. 



FICUS, Linn. 



Ficus primordialis, Heer. 



"Phyll. Cr«t. du Neb.," p. 16, pi. iii, fig. 1. 



Leaves coriaceous, lanceolate, narrowed to the base, very entire, penninerve; 

 lower pair of secondary veins at a very acute angle of divergence from the midrib, the 

 others more open, all camptodrome. 



I refer to this species two specimens (Nos. 26 and 33, Museum Comp. 

 Zool., Cambridge), representing: the one, the impression of the upper sur- 

 face of a lanceolate or oblong-lanceolate leaf, same size and shape as that of 



