274 UNITED STATES GEOLOGICAL SURVEY— TERTIARY FLORA. 



Habitat. — Washakie group, near Creston, Wyoming {Dr. F. V. Hat/den). 

 Carbon, Wyoming, where it is found, in numerous specimens, in the shale 

 under the main coal, with Poimlus arctica, Heer, etc. 



Pali III' us Florissanti, Lesqx. 



Plate L, Fig. 18. 



Paliuriis Florissanti, Lesqx., Annual Report, 1873, p. 410. 



Leaf small, lanceolate, slightly crenulate, three-nerved from above the base ; secondary nerves, 

 four or five pairs, parallel, the lower distant from the primary ones. 



This leaf, of which the point is broken, is very small, two and a half 

 centimeters long, one centimeter broad, of a hard, not coriaceous substance, 

 enlarged and rounded at the base to a short petiole, and gradually narrowed 

 upward. The nervation is of the same type as in the former species ; the 

 lower nerves, however, joining the midrib a little above the border base, 

 ascending in a curve and in a more open angle of divergence to below the 

 middle of the leaf, where they anastomose with the secondary veins, wiiich 

 curve in a series of equal single bows quite near tlie borders. This nerva- 

 tion is analogous to that of Paliurus acuJeatus, Lam., of Europe. 



Habitat. — Near Florissant, South Park, Colorado {Prof. E. D. Cope). 



Paliurus Kizyphoidcs, Lesqx. 



Plate LI, Figs. 1-6. 



Paliurus zizyphoides, Lesqx., Annual Eeport, 1872, pp. 384, 397. — Schp., Fal. Vdgdt., iii, p. Gil. 



Loaves subcoriaceous, entire, oval, obtusely pointed, cuncate, rounded or truncate to a thick 

 petiole, palraately five-nerved from the inflated base of the midrib; primary nerves branching, campto- 

 drome, like their divisions. 



These leaves, very variable in size, from two to seven centimeters both 

 ways, and nearly round, are also sometimes oval, narrowed in an equal degree 

 toward the point and to the petiole. The peculiar nervation seems to refer 

 them to the same species. The straight, somewhat thick midrib is abruptly 

 inflated above the base of the leaves, and the two or three pairs of primary 

 nerves are successively attached to it, the inner ones at the top of the inflated 

 part, the others lower. The lower lateral ones, either simple or branching, 

 ascend to near the middle of the leaves, the internal higher up, -sometimes 

 to near the point, anastomosing upward in bows, with the secondary nerves 

 placed, as in the former species, at a distance from the base. I do not tind 

 any affinity of this species with any of those known from the European Ter- 

 tiary; the nei-vation is comparable to that of Zizyphus j)iatyphyHa of Brazil. 



Habitat. — Erie, near Golden, Colorado; a single small leaf Black 

 Buttes, Wyoming, where it is not very rare. 



