158 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.54. 



Midrib tliin, generally somewhat curved. Normally there is a basi- 

 lar or subbasilar aerodrome primary on either side diverging from 

 the midrib at varying angles and merging with the secondary vena- 

 tion at or above the middle of the leaf. Sometimes a primary is 

 developed on only one side and even when there is one on each side 

 they are somewhat unlike in their courses since they tend to be 

 parallel with the lateral margins of the leaf which are somewhat 

 unsymmetric as compared with one another. There are two or three 

 pairs of arched camptodrome secondaries above the primary or four 

 pairs in case a primary is not developed on one side. 



This species is known only from materials in the collection from 

 Potosi studied by Britton and may therefore have been less common 

 than the bulk of the fossil flora where the general representation runs 

 remarkably uniform for the thi'ee collections studied. 



Cuphea is a large modern genus with about 160 existing species of 

 herbs and shrubs, otherwise unknown in the fossil state. With the 

 exception of Ouphea halsamona of the Galapagos and Sandwich 

 Islands it is confined to America and there chiefly in the equatorial 

 and subtropical regions. Cuphea viscosissima Jacquin is the only 

 North iVmerican species that extends northward beyond the Gulf 

 States. There are over 50 species in Mexico and many extend south- 

 ward along the Andes. There are 77 species in extra tropical Brazil. 

 These are several species in the moister parts of the Peruvian eastern 

 Andes; thus Cuphea cordata is an under shrub which extends upward 

 in the less arid parts of this region to elevations of 7,500 feet. The 

 distribution of Cuphea in the existing flora of Bolivia is unknown, 

 but the genus is represented in the Santa Cruz and Cochabamba 

 regions of eastern Bolivia. 



GAMOPETALAE. 

 Order ERICALES. 



Family VACCINIACEAE. 



Genus GAYLUSSACIA Humboldt, BonpLind, and Kunth. 



GAYLUSSACIA TERTL4RIA Engelhardt. 



Gaylussacia tertiaria Engelhaudt, Sitz. Naturw. Gesell. Isis in Dresden, 1894, 

 Abh. 1, p. 6, pi. 1, figs. 8, 9. 



Description. — Leaves spatulate or oblong lanceolate in outline, 

 with an acuminate apex and a more gradually narrowed acute base. 

 Margins entire. Texture coriaceous. Length ranging from 2.5 to 

 3 cm. Maximum width, in the middle part of the leaf, about 5.5 

 mm. Petiole missing, or absent. Midrib stout and prominent. 

 Seconlaries numerous, thin, and camptodi*ome. 



