170 DESCRIPTION OF SPECIES. 



are broader, less unequal than in F. Heerii, rounded or narrowed on one 

 side to a short petiole ; the camptodrome veins follow close to the bor- 

 ders, not curving inside to the medial nerves, and the borders are always 

 distinctly serrate. In F. juglandina the borders are sharply denticulate 

 and the more open lateral veins do not ascend higher along the borders, 

 as in the American species. 



Hob.— Florissant. U. S. Geol. Expl. Dr. F. V. Hat/den. 



F rax in us abbreviata, sp. nov. 

 Plate XXVIII, Figs. 5, 6. 



Leaves short, ovate, acute, round or truncate at base, sbort-petioled, denticulate ; 

 secondary nerves close, parallel, open, curved in passing to the borders, much branch- 

 ing outside. 



These leaflets, subequilateral, 3 to 5 centimeters long, 2 to 3 centi- 

 meters broad, with borders equally cut in acute small teeth slightly turned 

 upward, have the lateral nerves close. 10 pairs, at an angle of divergence 

 of 60°, somewhat curved in traversing the areas, much divided near the 

 borders, the branches entering the teeth directly or by anastomosing 

 veinlets. The nervation is like that of Fraxinus ulmifolia, Sap., "Et.," iii, 

 p. 91, pi. ix, figs. 17-19, differing essentially by shorter, comparatively 

 broader, more equilateral leaflets, and less acute, more equal teeth. The 

 relation of the species is very close. 



Hub. — Florissant. U. S. Geol. Expl. Dr. F. V. Hoyden. Seen also in 

 Lacoe Cabinet, No. 26. 



Fraxinus? myricae folia, ep. nov. 



Plate XXXIII, Figs. 13, 14. 



Leaflets small, sessile, subcoriaceous, narrowly lanceolate, distantly dentate ; 

 secondary nerves very oblique, mostly obsolete. 



The relationship of this fragment of leaf is obscure. The lateral 

 nerves are obsolete and the leaflets sessile. Though the leaflet, fig. 14, has 

 the same thick texture, the nerves scarcely distinct, it seems different on 

 account of its short petiole and the direction of the secondary nerves, 

 which is at an acute angle of divergence, apparently toward the teeth as 

 ciaspedodrome. It may be a leaf of Myrica. 



Hub.— Florissant. U. S. Geol. Expl. Dr. F. V. Haydcn. 



