154 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.54. 



Engler of the Argentina steppes and eastern Bolivia plains (Santa 

 Cruz, Cochabamba). It is one of the few fossil species found at 

 Potosi that is clearly indicative of arid conditions, and this may- 

 be due to its having grown on a porous slope where insolation was 

 great — i. e., it may reflect edaphic rather than climatic conditions. 



The fragmentary specimens described by Engelhardt as Mimosites, 

 species * and Mimosa montanoides^ ^^^y, and probably do, represent 

 this species. 



Plesioty pes. —Cat. No. 35109, 35110, U.S.N.M. 



Family EUPHORBIACEAE. 



Genus EUPHORBIA Linnaeus. 



EUPHORBIA (?), species, Britton. 



Euphorbia (?), Britton, Trans. Amer. Inst. Min. Eng., vol. 21, 1903, p. 256, figs. 

 59, 60. 



Description. — This record was based on an obscure specimen 

 preserved in a coarser grained rock than the balance of the Potosi 

 flora and considered by Britton to possibly represent a nodulose 

 stem of some fleshy Euphorhia such as still characterize the existing 

 flora in parts of South America. Nothing like it is contained in the 

 collection studied by me. 



Order PARIETALES. 



Family PASSIFLORACEAE. 



Genus PASSIFLORA Linnaeus. 



PASSIFLORA CANFIELDI Britton. 



Plate 18, figs. 4, 5. 



Passiflora (?) canfieldi Britton, Trans. Amer. Inst. Min. Eng., vol. 21, 1893, 

 p. 256, figs. 12, 13. 



Description. — Leaves small, sessile, palmately trilobate. Margins 

 crenulate. Texture coriaceous. Length about 1.5 cm. Maximum 

 width, from tip to tip of the lateral lobes, about 1.4 cm. Sinuses rec- 

 tangular, extending about halfway to the base. Central lobe broadly 

 rounded distad with subparallel sides, much longer than the lateral 

 lobes, its dimensions about 9 mm hj about 5 mm, hence nearly twice 

 as long as wide. Lateral lobes short, tending to be more narrowly 

 rounded than the median lobe, their upper margins straighter than 

 their lateral margins, which are full and curved to the broadly rounded 

 base. The basal half of the leaf forms an almost exact semicircle and 

 the crenulations of the margin become obsolete in the basal region. 



1 Engelhardt, H., Isis in Dresden, 1894, Abh. 1, p. 11, pi. 1, figs. 48, 49. 



2 Idem, p. 10, pi. 1, fig. 64. 



