510 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



Formation and locality. — Tertiary strata, Cook's lulet, Alaska. Col- 

 lected by Captain Howard, U. S. N. 



3G. Ilex microphylla, n. sp. 



Leaves small, short-petioled, ovate, slightly decurreut on the petiole, 

 abruptly pointed above, often unsymmetrical ; margins set with 3 to 5 

 spiny teeth on each side ; nervation distinct, but open, about 4 pairs 

 of branches springing from each side of the midrib, arching upward, 

 terminating in the teeth of the margin ; tertiary nervation consisting 

 of a coarse, irregular reticulation. 



Formation and locality. — Tertiary strata, near Fort Union, Dakota. 

 (Dr. Hayden.) 



37. Celtis kugosa, n. sp. 



Leaf long-ovoid to lanceolate, rounded and slightly heart-shaped at 

 the base, long-pointed at summit, 7 to 12 centimeters long by 3 to 5 

 centimeters wide ; margins set with coarse, obtuse teeth, undulate or 

 ■rarely entire; nervation strong, flexuous; midrib undulate; lateral 

 branches about six on each side, branching and interlocking near the 

 margins ; tertiary nervation transverse, parallel, strong. 



Formation and locality. — Tertiary strata, Tongue River, Wyoming. 

 Collected by Dr. Hayden. 



38. Celtis parvifolia, n. sp. 



Leaves small ; oblong-ovate in outline ; rounded and unsymmetrical 

 at the base, pointed at the summit; margins, except at the base, coarsely 

 dentate: nervation sparse; two principal branches on each side of the 

 midrib, one pair springing from the base and throwing off branchlets, 

 another strong pair issuing from the midrib at the middle of the leaf, 

 other delicate branches given off near the summit. 



Formation and locality. — Tertiary strata. Tongue River, Wyoming. 

 (Dr. Hayden.) 



39. Cercis eorealis, u. sp. 



Leaves small, orbicmlar, or roundish ovate ; blunt pointed, cordate at 

 the base ; margins entire ; nervation delicate ; midiib llexuous, about 

 three lateral branches on each side, the basal pair throwing off" several 

 branchlets on the lower side and reaching- to or above the middle of the 

 leaf. 



Formation and locality. — Tertiary beds, \'alley of the Yellowstone 

 River, Wyoming. Associated with Platanun Baynoldsii, N, Rhamnus 

 parvifolius, N, and Aristolochia orassifolia, X. (Dr. Hayden.) 



40. Fraxinus affinis, n. sp. 



Leaves petioled, lanceolate, long pointed, attenuate at base; margins 

 coarsely and irregularly toothed at and above the middle. 



