PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 507 



flabellate, consisting of a median and two principal lateral nerves, 

 which give off numerous branches. 



Formation and locality. — Tertiary strata, Yellowstone River, Wyom- 

 ing. Collected by Dr. Hay den. 



21. JUGLANS DENTATA, U. sp. 



Leaves large and relatively broad, 7 inches long by 2^ inches wide ; 

 short petioled ; roundgd, narrowed or unsymmetrical at base, marked 

 with remote, appressed, somewhat coarse, teeth ; nervation distinct and 

 regular; midrib straight, strong; lateral nerves about 12 pairs on each 

 side, arched upward, much curved toward the extremities, deflected along 

 the margin, finally terminating below in the marginal teeth, above, 

 camptodrome ; tertiary nervation forming a complicated and irregular 

 but sharpjy defined net-work. 



Formation and locality. — Eocene strata, Green Eiver Station, Wyo- 

 ing. Collected by Dr. C. A. White. 



22. JUGLANS OCCIDENTALIS, U. sp. 



Leaves somewhat variable in form and size, from 3 to 8 inches in length 

 and 1 to 2 inches in width, but generally 6 inches long by 1^ inches 

 wide, broad-lanceolate in outline, widest in the middle, summit acute, 

 base rounded, often unsymmetrical; margin sen tire; nervation delicate; 

 midrib straight ; lateral nerves, about twenty on each side, gently curved 

 upward, the lower ones branched and anastomosing near their extrem- 

 ities, the upper sim])le and terminating in the margins ; tertiary nerva- 

 tion very delicate, or obscure from being buried in tbe parenchyma of 

 the leaf, forming an open and irregular network. Fruit small, elongated, 

 somewhat prismatic ; divisions of the envelope lenticular in outline, nar- 

 row, thin. 



Formation and locality. — Eocene Tertiarj^, Green River, Wyoming. 

 Collected by Dr. C. A. White. 



23. Crategus flavescens, n. sp. 



Leaves small, about 1 inch in length and breath ; lobed; lobes rounded 

 and bearing a few teeth or crenulations ; the summit of the leaf trilobed, 

 with two lateral lobes below on either side. 



Formation and locality. — Miocene? Tertiary, Bridge Creek, Oregon. 

 Collected by Prof. Tliomas Condon. 



24. Ulmus speciosa, u. sp. 



Leaves 4 to (J inches in length by 2 inches in width ; petioled, long- 

 ovoid, or elliptical in outline, pointed at summit ; margins coarsely and 

 doubly serrate; nervation strong, regular, 15 to 20 parallel branches on 

 either side of the midrib. Fruit large, 27 centimeters in diameter, sub- 

 circular, emarginate. 



Formation and locality. — Tertiary strata, Bridge Creek, Oregon. Col- 

 lected by Prof. Thomas Condon. 



