with Description* of X w -\ eoiesqfu 



distinctly three-veined than that of any living i 

 Populus. This character, with the Bmooth Burface and nearh 

 entire margins, gives these leaves the general aspect of thos. 

 Smilax, and suggested the name given them. Their oer 

 however, is sufficiently distinct from that of Smilax, an 

 clearly that of Populus, though in a Bomewhat ea ,:,..| 



form. In Smilax three or five nerves radiate from the baa 

 the leaf, and termvnajU together at th< summit, which lim- 

 ine leaves of Populus never do. In Smilax, too, the principal 

 nerves give oft* no large branches, but all the interspa 

 filled with a- labyrinth of anastomosing veins, formings von 

 different network from that of Populus. 



The marginal serration of the present Bpeciee would 

 have been much like that of the leaves of the living /'. tn 

 loides, but still finer, while the size of the leaf was considera- 

 bly larger. 



Formation and Locality. Miocene Lignite Tertiary. 1 

 Union, Dacotah. (Dr. Hayden.) 



PlataiiiiM nohili*. (n. Bp.) 



Leaves large, one and a half feet in length and breadth, p" 

 oled, 3 lobed, or sub 5 lohed, lobes acute, margins of lobes and 

 base entire, or near the summits of the loins delicately sitr: 

 toothed; nervation strongly marked, generally parallel; tm 

 nerve straight, two basilar nerves of nearly equal length 

 strength diverge from it at an angle of 30 

 throughout and terminate in the apices <<( thi 

 lobes. Above the basilar nerves about 16 pairs of latei 

 are given off from the midrib al about the Bame ancle; tl 

 nearly straight and parallel, terminating in the teeth of '•'■ 

 From each of the basilar nerves dii erge about the sam< 

 pairs of branches as from the midrib, and the • 

 straigh.1 and parallel, ami terminate directly in the in 

 these the second or third exterior one on each side 

 the strongesi of the series, and is then pr 

 distinct lateral, triangular, acute lobe, giving 

 pentagonal form. Prom this basilar branch of the ! 

 12 or more short, generally simple, bra 



