Gress: Fossil Plants of the Dakota. 311 



was not completely exposed. On removing some of the overlying 

 stone, it was found to be a five-lobed leaf very different in outline 

 from what it appeared to be before the removal of this overlying 

 stone. It somewhat resembles Cissitcs, but does not fit any described 

 species, with which I have been able to compare it. It resembles more 

 closely than any other species Cissitcs ingcns var. parvifolia Lesq. 

 (Flora of the Dakota Group, 1892. PI. 57, fig. 3), but differs in the 

 branching of the primaries at the base of the leaf, also in its more 

 cuneate base and lobed or toothed margin. It resembles so closely in 

 outline and venation our modern Platanus occidenfalis that I have 

 named it Platanus cissitifolins. The leaf is five-lobed, nearh 6 cm. 

 long, and about the same width between the apices of the two upper- 

 most lateral lobes. It is palmately three-veined ; the two lateral pri- 

 mary veins originate about 5 mm. from the base of the leaf and 

 extend into the two uppermost lateral lobes. Each lateral primary 

 vein sends out a branch from its lower side about 1.5 cm. from the 

 base of the leaf, which extends to the lowermost lateral lobe. The 

 margin is sinuate or toothed. The tertiary venation resembles very 

 closely that of our modern Platanus occidentalis. 



Family ROSACE.^. 

 Genus Pyrus. 



38. Pyrus cretacea Newberry. 



Pyrus cretacea Newberry, Annals N. Y. Lyceum Natural History, IX, April, 

 1868, p. 12 ; The Later Extinct Floras of North America, U. S. Geological 

 Survey, Monograph XXXV, 1898, p. no, PL i, fig. 7. 



Lesquereux, Illustrations of Cretaceous and Tertiary Plants, 1878, Pi. 2, 

 fig. 7 ; The Cretaceous and Tertiary Floras, U. S. Geological Survey of the 

 Territories. VIII, 1883, p. 86; The Flora of the Dakota Group, U. S. 

 Geological Survey, Monograph XVII, 1892, p. 144 (name and reference only;. 



Description: The leaf is very small, being about 1.5 cm. long and 

 of the same width. It fits very closely Newberry's description, which 

 follows : " Leaves petioled, small, roundish, oval or elliptical, often 

 slightly emarginate, entire or finely serrate; medial nerve strong be- 

 low, rapidly diminishing toward the summit ; lateral nerves four or 

 five pairs, with intermediate smaller ones, diverging from the midrib 

 at unequal angles, curved toward the summit, where they anastomose 

 in a series of arches parallel with the margins; tertiary nerves form- 

 ing a network of which the areoles are somewhat elongated." 



AXN. CAR. MUS., XIII. 21. FEB. 21, I922. 



