178 DESCRIPTION OF SPECIES. 



Weill III iv II II i ;i H a y <I <> n i i , Lesqx. 

 Plate XLII, Figs. 1-7. 

 Shus naydenii, Lesqx., "U. S. Geol. Rep.," vii, ji. 294, pi. Iviii, fig. 12. 



Leaves imparipinnate ; racliis winged ; leaflets opposite or alternate, sessile, 

 membranaceous, narrowly lanceolate, obtusely .serrate ; nervation pinnate, craspetlo- 

 drome ; nervilles at right angles to the secondary veins, anastomosing in the middle of 

 the areas and forming a small polygonal areolation. 



The rachis is winged and nerved ; the leaflets are joined to the midrib 

 by their primary nerves, and their borders are continued at base by a 

 narrow margin along the rachis. 



Hah. — Florissant. Very abundant ; seen in all the collections. The 

 figures are from specimens obtained by the U. S. Geol. Expl. Dr. F. V. 

 Hayden. ^ 



Weinmannia Integrifolia, ep. nov. 



Plate XLII, FigB. 8-13. 



Leaves narrower than in the preceding species ; leaflets narrow, entire, oblong 

 or subliuear, blunt at the apex, more distinctly turned upward ; nervation camptodrome. 



Except that the leaflets are narrower and entire and the nervation 

 consequently camptodrome, the characters are the same and this form 

 may represent only a distinct variety. The leaves of these two species are 

 polyphyllous, the number of their leaflets being much greater than in any 

 other species living at this epoch. This difference and the nearly linear 

 wing of the petiole relate them to Bhus. 



Hah. — With the preceding and quite as common. 



Wei 11 man Ilia obtusifolia, sp. nov. 

 Plate XLI, Figs. 4-10. 



Leaflets close, the upper pairs decurrent and connate at base, the lower more 

 distant, bordering the rachis by their decurrent base; wing obtusely dentate or con- 

 vex in the middle ; leaflets oblong-obtuse or subspatulate, very entire, more rigid than 

 in the two preceding species, membranaceous ; nervation camptodrome. 



As in the other species, the leaflets are alternate or opposite, narrowed 

 toward the base or larger toward the obtuse or rounded apex; the leaves 

 are generally smaller, shorter, Avith fewer leaflets. 



Hah. — Florissant; not as frequent as the two preceding ones. 



