DESCRIPTIONS OF SPECIES. Ill 



Amelanchiee similis Newb. 



PI. XL, fig. 6. 



Ann. 1ST. Y. Lye. Nat. Hist., Vol. IX (April, 1868), p. 48; Ills. Cret. and Tert. PI. 

 (1878), PI. XXV, fig-. 6. 



"Leaves petioled, ovate, obtuse or acuminate, rounded or slightly 

 cordate at the base; margin coarsely toothed, except near the petiole, 

 where it is entire; nervation pinnate, delicate; medial nerve straight, six to 

 seven pairs of lateral nerves diverging from the midrib at an angle of 

 about 40 degrees, slightly curved upward, especially near the summit, 

 the upper ones nearly simple, but giving off a perceptible branch near the 

 summit on the lower side, which runs into the next tooth below. The 

 lower pair spring from the extreme base of the leaf, are strong and simple, 

 and strike the margin where the dentation commences. The second pair 

 of lateral nerves each send off two or three slender nerves from near the 

 summit to the teeth of the adjacent margin; tertiary nerves very fine, 

 leaving the secondaries at right angles, and forming a fine network of 

 which the areolae are nearly quadrate." 



Collected by Dr. F. V. Hayden. 



The number of specimens of this species in the collection is small and 

 all but one are imperfect. This one is the impression of a thin, delicate 

 leaf, of which all the details of nervation are preserved as perfectly as they 

 could have appeared in the living plant. The other specimens indicate 

 that the leaves were usually pointed, often acute. 



From the nervation and character of dentation of these leaves, I think 

 we may at least say that the plant which bore them was Rosaceous, and 

 among the Rosaceous genera with which I have compared them they 

 approach most nearly to Amelanchier, some of the leaves of A. Canadensis 

 being entirely undistinguishable from them in form or nervation. 



A. Canadensis now grows over all the temperate parts of the continent 

 and would seem from its wide range to be an old resident of the conti- 

 nent and as likely to be represented in the Tertiary as any other of our 

 plants. 



Formation and locality: Tertiary (Eocene?). Banks of Yellowstone 

 River, Montana. 



