136 



ley* antedates Unger's name by about four years. In the 

 determination of Smilax leaves there is indeed a large element of 

 uncertainty, owing to the variation in outline, as Laurentf 

 has beautifully illustrated in the case of 6". aspera. This should 

 prevent us from multiplying specific names based on dififerent 



Fig. I. Smilax labidiiroynmx Cockerell. 



looking leaves of the same region and period, but on the other 

 hand, it should not lead us to consider identical plants of quite 

 different parts of the world and difYerent geological horizons. 

 Something must be allowed for the inherent probabilities in 

 each case. KnowltonI has described Smilax lamarensis from the 

 supposed Miocene of the Yellowstone ; it resembles S. carhonensis 

 rather than the Florissant species, having the cordate base and 

 rounded sides. Heer,§ from beds supposed to be Miocene at 

 Asakak, Greenland, describes a Smilax lingulata; it is a narrow 

 leaf quite unlike the Florissant plant, resembling, in fact, the 

 living S. laiirifolia L. 



A much more ancient plant assigned to this genus is Smilax 



* Am. Journ. Sci. 45: 171. 1843. 



t Ann. Mus. Marseille, 12: pi. i. (1908.) 



X Geol. Yellowstone Nat. Park, pi. CXXI, f. 3, 4. 



§ Kongl. Sv. Vet. Akad. Handl., 13, no. 2: 15, pi. i, f. 12 (1874). 



