32 THE LATER EXTINCT FLORAS OF NORTH AMERICA. 



the leaf; but it is probable that they were joined to the margin. Until 

 more complete specimens of this plant shall be obtained nothing' positive 

 can be said of its relations to living palms; but it is evidently allied to 

 Heer's Manicaria formosa (Fl. Tert. Helv. I, p. 92, PI. XXXVIII), and to 

 the living Manicaria of South America. It certainly also belongs to the 

 same genus with Lesquereux's palm leaves which he has grouped under 

 the new generic name of Geonoinites, but it has seemed to the writer more 

 closely allied to Mannicaria than Geonoma. Its specific relations are also 

 somewhat doubtful. It most resembles Geonomites tenuirachis Lesq. (Tert. 

 FL, p. 117, PL XI, fig. 1), but in the figured specimen of that plant the 

 folds of the leaf spring from the midrib at a much more acute angle than 

 in the specimen before us. This difference could be reconciled if it were 

 certain that Lesquereux's specimens came from near the summit of the 

 leaf, where the folds generally approach the direction of the midrib. Dr. 

 Hayden reports the specimen to which the name of Geonomites tenuirachis 

 was given as coming from the Raton Mountains and from strata which are 

 older than that which furnishes the specimen now described. So far as 

 now known there are no species common to the Raton Mountain beds and 

 the Green River Tertiary. There is a strong probability, therefore, that 

 the differences indicated have specific value. 



Formation and locality: Tertiary (Green River group). Green River 

 Station, Wyoming. 



Order SMILACE^. 



Smilax cyclophylla Newb. 

 PL LIV, fig. 3, in part. 

 Boston Journ. Nat. Hist., Vol. VII (1863), p. 520. 



" Leaves circular or round, ovate, cordate or slightly peltate at base, 

 five-nerved, central and interior pair of lateral nerves strongly marked, 

 basilar pair delicate and scarcely reaching the middle of the leaf; second- 

 ary nervation forming a polygonal network more or less rectangular." 



Unfortunately, the only specimen of this plant which I have — that 

 collected by Professor Dana and figured in his Geology of the United 

 States Exploring Expedition, Atlas, PL XXI, fig. 10 — is imperfect, the 

 upper part of the leaf being wanting. So far as its outline is indicated by 

 the part which remains, it would seem to have been nearly orbicular. If 



