116 THE LATER EXTINCT FLORAS OF NORTH AMERICA. 



age, it would be a fact of no little interest, and would strengthen the claims 

 of Negundo aceroides to a distinct generic place in the botanical series. In 

 that case, however, its trilobate terminal leaflet would still further indicate 

 its acerine affinities. 



Formation and locality: Tertiary (Fort Union group). Fort Union, 

 Dakota. 



Order SAPINDACE^E. 



Sapindus affinis Newb. 



PI. XXX, fig. 1 ; XL, fig. 2. 



Ann. N. Y. Lye. Nat. Hist., Vol. IX (April, 1868), p. 51; Ills. Cret. and Tert. PI. 

 (1878), PI. XXIV, fig. 1 ; XXV, fig. 2. 



"Leaves pinnate in many pairs of leaflets, with a single lanceolate 

 terminal one; leaflets smooth, thick, lanceolate, long-pointed, acute, sessile 

 or short-petioled, unsymmetrical, rounded or wedge-shaped at base; nerves 

 fine and obscure, ten or more branches diverging from the midrib on either 

 side at somewhat unequal distances, and of unequal size. These arch 

 upward, giving off several lateral branches at right angles, or nearly so, 

 and die out near the margins, or are carried around in a curve parallel with 

 it, and thus connect." 



Collected by Dr. F. V. Hayden. 



These leaves are most strikingly like those of Sapindus, and taken by 

 themselves would afford perhaps sufficient ground for uniting them with 

 that genus. They are also very like a series of leaves found in the 

 Tertiaries of Europe, figured by Professor Heer, in Fl. Tert. Helv., Vol. 

 Ill, p. 61, Pis. CXIX, CXX, CXXI; under the names of Sapindus falci- 

 folius, S. densifolius, and S. dubius. The nervation is also the same; so 

 there can hardly be a doubt that our plant and those of Professor Heer are 

 generically identical, and, if the proofs before him of the identity of his 

 fossils with the living genus Sapindus are sufficient, we must conclude that 

 the specimens before us are also the representatives of that genus. In our 

 specimens, however, the leaves are constantly shorter and broader than in 

 the species I have mentioned, and are often rounded at the base, so that I 

 have been compelled to regard them as specifically distinct. 



Formation and locality: Tertiary (Eocene?). Mouth of Yellowstone 

 River, Montana. 



