DESCRIPTION OF SPEOIES. 145 



nervation, it is very similar to A. percfjer Ung-., as figured in the Flora von 

 Sotzka (p. 54, PI. XXXIV, Figs. 10-16), or as it is figured in Ludwig's Foss. 

 Pfl. Rhein.-Wett. Tertiar-Forni. (p. 143, PL lix, Figs. 3, 4), where the leaves 

 are represented as entire. In this connection Schiuiper remarks tliat the 

 leaves appear rather to be those of" Sapindus, especially on account of their 

 'jntire borders. The leaves of Prunus (Amygdalus) are as often entire as 

 serrate. I find no reason to refer this fine species to any unknown genus. 

 Habitat : Kansas. 



Order LEGUMINOS^E. 



Suborder C.ESALPINIE/li:. 



Tribe AMHERSTIE^E. 



Hymen^a dakotana, sp. nov. 

 PI. LV, Figs. 2, 3; PI. LVI, Figs. 1, 2; PI. LXII, Fig. 2. 



Leaves compound, of two, very rarely three, elliptical oi- oblong lance- 

 olate, entire leaflets, joined lower than the l)ase of the pinnules and there 

 obliquely parted; midrib narrow; secondaries oblique, parallel, curved in 

 traversing the blade, camjitodrome. 



The species has numerous representatives, generally single detached 

 leaflets, sometimes borne upon a short petiole, joined together, or very rarely 

 three, at a distance of V™ to 2'"° I)elow the basal borders and passing toward 

 a stronger, common petiole. Three of the specimens, the best presei*ved 

 ones, have been figured, as also a single one with three pairs of leaves. 

 The pinnules vary greatly in size and the more or less acute base, some 

 being more rounded in joining the petiole. The divergence of the second- 

 aries, of which there ai-e seven to eight paii-s, is also slightly variable, 

 being more or less open and variable in distance, even in the same leaves, 

 generally diverging 40° to 50° from the midrib. 



One leaf of this genus, H. primiqenia, is figured by Saporta in his Monde 

 des Plantes (p. 199, Fig. 2). The leaflets are joined nearer their base and 

 thus less distant; the same species figured and described by Velenovsky' 

 has the leaflets still larger than those of the Dakota Group specimens, but 

 with a shorter petiole, though longer than they are figured by Sajtorta, with 

 secondaries less numerous and more distant. The difference may not be 

 specific. The leaves figured by Velenovsky are slightly crenate, while they 



'Fl. bohm. Kreideform., pt. 3. PI. v, Fig. 4; PI. vi. Figs. 2-4. 

 MON XVII 10 



