18^7.] PROCilEDIXGS OF UNITED STATES NAflONAL MUSEUM. 39 



150. Quercus Crossii, n. sp. PI. II, Figs. 5, 6. 



Ryolite Bed, Silver Cliff, Colo. ; C. W. Cross, collector. 



Leaves small, coriaceous, convex on the upper face, obloug or ob- 

 lanceolate, cuneate at the base, abruptly round-pointed at the apex, 

 dentate, except toward the base ; mid-rib thick, straight ; secondaries 

 oblique, slightly curved in passing to the borders, nearly simple ; cras- 

 pedrome. 



Two small leaves, 3^ to 4 centimeters long, 1^ centimeters broad in 

 the upper part or above the middle, with 5-6 pairs of alternate or op- 

 posite secondaries diverging 30°-35o, curved in passing toward the 

 borders, thick and simple, except near the border, with somewhat ob- 

 solete nerviles at right angles. The leaves have a degree of affinity to 

 those of Quercus Mediterranea Ung., differing especially by the short, 

 less-acutely pointed teeth, very short toward the base, gradually larger 

 to the apex, similar, however, to the figure of this species in Heer. 

 Fl. Tert. Helv., Plate LXXVI, f. 15. 



With living species, the relation of the leaves is closely marked with 

 those of Quercus snber and Q. ilex, differing by the great thickness of 

 the nerves, especially the medial. They appear to have been short 

 petioled. Species named for the collector, Mr. C. W. Cross. 



Two specimens ; Museum number, 2329 ; lot number, 209. 



151. Quercus Drymeja Ung. 



Separation, Colo., 1881; Lester F. Ward, collector; one specimen; 

 Museum number, 2333; lot number, 22. 



152. Quercus Gaudini Ls. PI. II. Figs. 7, 8. 



Locality and collector unknown ; one specimen ; Museum number, 

 2330; lot number, 13. Upper Kauab Valley, Utah; C. D. Walcott, col- 

 lector; one specimen; Museum number, 2332; lot number, 8. 



153. Quercus imbricaria Mich, fossilis. 



Bridgeton, K. J. ; J. B. Marcou, collector ; two specimens , Museum 

 number, 2328; lot number, 207. 



154. Quercus neriifolia Al. Br. 



Locality and collector unknown; one specimen; Museum number, 

 2335 ; lot number, 13. 



155. Quercus Platania? Heer? 



Upper Kanab Valley, Utah; CD. Walcott, collector; one specimen; 

 Museum number, 2331 ; lot number, 8. 



SALICINE^. 



156. Salix proteaefolia ? Lx. 



Near Las Animas, Colo. ; Dr. C. A. WTiite, collector ; three specimens ; 

 Museum number, 2336; lot number, 4. 



157. Populus arctica Heer. 



Cascades, Oregon; A. Hague, collector; one specimen; Museum num- 

 ber, 2338 ; lot number, 20. 



