DESCRIPTION OF SPECIES— CORNER. 243 



the Lower Ligiiitic of Golden and Evanston. One has been described by 

 Dr. Newberry from numerous specimens found in the Lignitic of the Yellow- 

 stone River. They are all more or less intimately related to species of our 

 time. The Upper Tertiary or Pliocene of California has two very fine Cornu.s, 

 more closely allied to present species of the Pacific coast. They constitute 

 four per cent, of the whole flora known from that formation, indicating a 

 marked preponderance of the genus in the more recent formations. The 

 leaves of Cornus are easily recognized by their ovate, generally acuminate 

 Ibrm, and by the direction of the upper lateral veins, curving inside and 

 tending toward the point. 



Cornus suborbifera, sp. nov. 

 Plate XLII, Fig. 2. 

 Cornus orhi/era (Heer), Lesqs., Annual Report, 1873, p. 402. 



Leaves oval, rounded upward, and also rounded or truncate to a short petiole, entire; lateral 

 nerves on an open angle of divergence, much curved in traversing the areas; nervilles strong, oblique, 

 ■with cross-veinlets in right angle, forming loose, irregularly square meshes. 



I had considered this leaf as identical with C. orhifera, Heer (Fl. Tert. 

 Helv., iii, p. 27, pi. cv, figs. 15-17); but Comit Saporta, who has published 

 a leaf of the same species (fit., iii, p. 97, pi. xiii, fig. 3), has compared ours 

 with European specimens, and considers it difl^erent. The lateral veins are not 

 quite as regular in distance in the American leaf, and the nervilles are slightly 

 more oblique. It is, however, difficult to positively note the essential char- 

 acters of a species from a mere fragment like this; the upper part being 

 destroyed, and the real form being therefore uncertain. 



Habitat. — Golden, Colorado. 



Cornus imprcssa, Lesqs. 

 Plate XLII, Figs. 3. 

 Cornus impressa, Lesqs., Annual Report, 1873, p. 408. 



Leaves coriaceous, entire, regularly oval, rounded to a very short, scarcely distinct acumen, 

 rounded also in narrowing to the base; secondary nerves at an acute angle of divergence, camptoJrome 

 and aerodrome. 



This leaf, evidently coriaceous, its outUnes being deeply impressed into 

 the stone, is also, but more distantly, related to C. orbifera. The secondary 

 nerves, all simple, joined by strong nervilles, more distant and less oblique 

 than in the former species, pass up from the strong midrib in an angle of 

 divergence of about 40°, scarcely curve in traversing the areas, follow the 

 borders by a series of simple bows, anastomosing by the nervilles. The 



