FOSSIL FLORA. 735 



morphum, but differs in being much larger and in having more numerous 

 and closer secondaries. It is undoubtedly close to this species, and rather 

 than make it a new species I have referred it to this. 



Habitat: Yancey Fossil Forest, near the standing trunks; collected 

 by F. H. Knowlton, August, 1888. 



ACERACEiE. 



Acer vivarium n. sp. 

 PL XOVIII, fig. 4. 



Leaf membranaceous, palmately 3-lobed, narrowed below to a wedge- 

 shaped base, sinuses rounded, middle lobe lanceolate-acuminate, as long 

 or longer than the body of the blade below the sinuses; lateral lobes 

 at an acute angle (points not preserved); margins remotely toothed with 

 small, sharp, upward-pointing teeth ; midrib, or central rib, strong, straight, 

 slightly stronger than the lateral ribs, which arise from the midrib just 

 above the base of the blade at an angle of about 70° and pass up straight 

 to the points of the lateral lobes or curve slightly outward; lateral ribs 

 with several pairs of secondary branches, those on the outside beginning 

 just above the base of the blade and passing straight or with a slight 

 upward curve to or entering the teeth; secondaries on the upper or inside, 

 beginning below the sinus, which the lowest one enters, the others probably 

 entering the teeth; middle lobe with about 6 pairs of alternate second- 

 aries arising* at an angle of 70° or 75°, and passing up nearly straight, to 

 end in the teeth or fork just below the teeth, one branch entering and the 

 other going upward near the margin to the one above; nervilles numerous, 

 mainly percurrent; finer nervation beautifully preserved, forming quad- 

 rangular areolae. 



The example figured is the only one observed of this species. It is 

 about 10 cm. long and 6 cm. broad. The central lobe is about 5 cm. long 

 and a little more than 2 cm. wide. The lateral lobes appear to have been 

 about 2 cm. wide and of an unknown length. 



This leaf belongs to the Acer trilobatum group, so many forms of which 

 were described by Heer from the Swiss Tertiary. In shape it is most like A. 

 trilobatum prodwtum, 1 but differs in having only very small, sharp teeth. It i 



s 



PI. Tert.. Helv., Vol. Ill, PI. CXV, figs. 6-12. 



