DESCRIPTIONS OF SPECIES. 115 



Order ACERACE^E. 



Acer sp.? Newb. 



PI. XL VI, fig. 8. 

 Note. — The only information which I have been able to obtain in regard to 

 this figure is the manuscript note, "Acer fruit," by Dr. Newberry, on the margin 

 of the plate, and the locality as given on the specimen label. — A. H. 



Formation and locality: Tertiary (Miocene). Bridge Creek, Oregon. 



Negundo triloba Newb. 

 PL XXXI, fig. 5. 



Ann. N. Y. Lye, Nat. Hist., Vol. IX (April, 1868), p. 57; Ills. Cret. and Tert. PI. 

 (1878), PI. XXIII, fig. 5. 



"Leaves thin and delicate, but distinctly nerved, pinnate in one or 

 more pairs, leaflets lanceolate or lance-ovate, long-pointed, rounded or 

 slightly cordate at base, short-petioled; margins coarsely, remotely, and 

 irregularly toothed; terminal leaflet trilobate, the margins toothed or ser- 

 rated; nervation of lateral leaflets pinnate, nine or ten pairs of lateral 

 nerves diverging from the midrib at an angle of about 50 degrees, arching 

 upward, more or less branched toward the summit, Of these the basal 

 pair are shortest and simple, following the course of the adjacent margin; 

 the second pair are strongest, and throw off each three or four curved 

 branches on the lower side." 



Collected by Dr. F. V. Hayden. 



The general aspect, including texture, form, dentation, and nervation 

 of the lateral leaflets is strikingly like that of the corresponding parts of 

 the leaf of the living Negundo aceroides. The genus Negundo is represented 

 among living plants by but a single species, and this is so like Acer in all 

 but its leaves that Professor Gray intimates that it should hardly be con- 

 sidered distinct from that genus. A fossil species has been discovered in 

 the Tertiaries of Europe, N. Europceum Heer (Fl. Tert, Helv, Vol. Ill, 

 p. 60, PI. CXVIII, figs. 20-22), but it would seem to have been a smaller 

 species than the living one, and had obovate wedge-based leaves quite 

 different from those before us. 



If, in the light of more and better material, it should prove that a 

 species of Negundo lived on the American continent during the Tertiary 



