28 FOSSIL FLORA OF THE SIEEEA NEVADA. 



ZIZYPHUS, Mill. 



Zizyphus microphyllus, sp. nov. 



PI. VIII. Fie/. 9. 



Leaves small, subcoriaceous, oblong, rounded to the base ; primary lateral veins from 

 above the base, subacrodome ; borders minutely serrulate. 



By its form, size, and the minutely serrate borders, this leaf has an 

 analogy to species of Ceanothus, especially to the small form of C. vehitinus, 

 Dough, whose basilar lateral nerves, however, come out from the base of 

 the leaves. I do not know any fossil species to which this fragment 

 might be compared. Like that of the former, the specimen should per- 

 haps have been left undescribed. These leaves may be, however, useful 

 for future comparison. 



Habitat. — Chalk Bluffs, California. Professor J. D. Whitney. 



Zizyphus piperoides, sp. nov. 

 PI. VIII. Figs. 10, 11. 



Leaves subcoriaceous, entire, lanceolate, acuminate, rounded to the petiole ; lateral primary 

 nerves subacrodome, joined to the mid rib in. an acute a ugh: of divergence, and 

 slightly decurving to it. 



The characters of nervation of these leaves are the same as in the 

 former species. The lateral primary veins from above the base of the 

 leaves ascend at a distance from the borders to near the point, anasto- 

 mosing with the secondary veins, as seen in Fig. 11, and more or less 

 branching outside ; under them there is a pair of basilar veinlets follow- 

 ing up, parallel to the borders. Rounded at the base, these leaves are 

 gradually narrowed into an apparently long acumen. They vary in size 

 from six to ten centimeters long, and from two to three centimeters 

 broad a little above the base, where they are broader. The midrib, which 

 is strong, is in its lower part joined to the lateral nerves by indistinct, 

 irregular veinlets, and divided upwards in alternate distant branches, 

 which curve and anastomose in bows at a distance from the borders. The 

 details of nervation and of areolation are obsolete. The forms and ner- 

 vation are like those of the leaves of many species of Piper. 



Habitat — Chalk Bluffs, California. Toy's Collection. 



