DESCRIPTION OF SPECIES— LEGUMINOS^. 299 



shorter tertiary veins anastomosed by nervilles in right angle. This nervation 

 is typically identical with that of P. Knorrii, Heer (Fl. Tert. Helv., iii, p. 

 114, pi. cxxxiv, figs. 22-26; cxxxv; exxxvi, figs. 1-9); the leaflets of our 

 pi. lix, fig. f), and pi. Ixiii, fig. 2, corresponding to fig. 4, pi. exxxvi, and that 

 of our pi. Ixv, fig. 5, to fig. 3 of the same plate of Heer. The shape of the 

 leaflets and their size, though comparable also to those of P. Knorrii, 

 differ by the longer, sharply pointed acumen, and by the longer slender petiole 

 not inflated at its point of union to the middle nerve. The fragment of cap- 

 sule, described in Annual Report, 1873, p. 417, as referable to a Podogonii/m 

 species, is pedicellate, apparently oval, but broken below the middle, and 

 cannot be specifically identified. It may represent the same species. 



Habitat. — The first of the specimens is from Black Buttes, Wyoming; 

 the second (pi. Ixiii), from Middle Park, Colorado (Dr. F. V. Hayden), 

 with the broken capsule; the third (pi. Ixv), from near the mouth of White 

 River, Green River group, Wyoming {Prof. W. Denton^. 



CASSIA, Linn. 

 Cassia conciniiat , Heer. 



Plate LIX, Figs. 8, 8 o (enlarged). 

 Cassia concinna, Heer, Fl. Tert. Helv., iii, p. 122, pi. cxsxviii, fig. 41. — Lcsqx., Annu.il Report, 1872, p. 402. 



This fragment of an unfolding leaflet is like the undeveloped ones 

 figured by Heer, loc. cit.; the middle or dorsal nerve is thick and the lamina 

 folded along the lateral nerves. As we have a single leaflet for comparison, 

 this similarity is not sufficient for identification. 



Habitat.— Evanston, Wyoming. 



ACACIA, Neck. 

 Acacia scpteiitrionaiis, Lesqz. 



Plate LIX, Figs. 9, 9 a (eularged). 



Acacia septenirionalis, Lesqx., Annual Report, 1873, p. 418. 



Leaflet small, coriaceous, oblanceolate, rounded to a very ftliort point, gradually tapering down- 

 ward to the short petiole; nervation pinnate, aerodrome. 



This small leaflet, two and a half centimeters long, and four millimeters 

 broad toward the rounded point, has the lateral nerves alternate, ascending 

 nearly parallel to the midrib, the upper one reaching the point in an inside 

 curve, all anastomosing in oblique veinlets, composing long equilateral meshes; 

 these veins are very thin, discernible only with a strong glass; the surface is 



