NO. 2229. FOSSIL PLANTS FROM BOLIVIA— BERRY. 153 



LEGUMINOSITES, species. 



Plate 18, fig. 1. 



Description. — ^A small leguminous leaflet, ovate in form, with a 

 rounded tip and greatly inequilateral base. Margin entire. Length, 

 about 3 mm. Maximum width about 1 mm. Midrib stout and 

 curved. A stout ascending secondary from its base on each side 

 gives the leaflet a triveined appearance. Distad there are two 

 pairs of thin camptodrome secondaries. 



This may be a distmct species. As it is represented by only a 

 single specimen, it is not considere4 wise to make it the basis of a 

 new species, especially as it may represent a variant of the abundant 

 Calliandra obliqua Engelhardt. 



Holotype.—C&t. No. 35108, U.S.N.M. 



Order GERANIALES. 



Family ZYGOPHYLLACEAE. 



Genus PORLIERIA Ruiz and Pavon. 



PORLIERU TERTURIA Britton. 



Plate 18, figs. 2, 3. 



Porlieria tertiaria Britton, Trans. Amer. Inst. Min. Eng., vol. 21, 1893, p. 251, 



figs. 71-75. 

 Mimosites, species, Engelhardt, Sitz. Naturw. Gesell. Isis in Dresden, 1894, 



Abh. 1, p. 11, pi. 1, figs. 48, 49. 



Description. — Leaves opposite, subsessile, evenly pinnate in my 

 specimens, but odd pinnate in the type material. General outline 

 elliptical or obovate. Length, ranging from 6 to 9 mm. Maximum 

 width, at or above the middle, 3 to 5 mm. Leaflets sessile by a but 

 slightly narrowed base, 8 or 9 subopposite to alternate pairs with 

 sometimes an odd terminal leaflet, crowded especially distad, diverg- 

 ing at narrow angles both proximad and distad, especially one or two 

 distal pairs. In the middle part of the leaf the angle of divergence 

 ranges from 45 to 60°. Rachis relatively very stout. Texture 

 coriaceous. Leaflets linear oblong or slightly spatulate, with a 

 slightly narrowed, broadly sessile base and a rounded apex, slightly 

 inequilateral. Margins entire. Midribs thin and immersed. Length, 

 ranging from 1 to 2.5 mm. Maximum width one-half to one-fourth 

 the length. 



This species is not imcommon at Potosi. Porlieria is a small genus 

 of shrubby plants, with three or four existing xerophytic species, 

 found from Texas and Mexico southward to the Chilean Andes and 

 the Argentina steppes. The fossil species greatly resembles the 

 existing Porlieria Jiygrometi^ica Ruiz and Pavon of the arid country 

 between southern Peru and northern Chile and Porlieria lorentzii 



