COROCORO COPPER DISTRICT OF BOLIVIA 105 



Their maximum display is in the Amazon region, and they 

 do not appear to be represented in the present mountain 

 region of Bolivia. 



The known fossil species are few in number and com- 

 prise, in addition to the present form, three Oligocene and 

 a Miocene species in central and southern Europe. 



Genus Dalbergia LINNE fils 



Dalbergia antiqua ENGELHARDT 



PLATE VII Fig. 12. 



Dalbergia antiqua Engelhardt, Sitz. Naturw. Gesell. I sis in Dres- 

 den, 1894, Abh. i, p. 8, pi. i, fig. 23. 



Description. Small, coriaceous, indehiscent, stipitate 

 single seeded flat pods, obovate in outline, widest distad, 

 narrowed proximad to a short or slightly extended base, 

 vexillar margin straightest. Length ranging from 1.25 cm. 

 to 2.5 cm. Maximum width ranging from 7 mm to 10 mm. 

 Seed single, lenticular, about 4 mm. in diameter, located 

 near vexillar margin. The surface of the pod is ligneous 

 and marked with anastomosing diagonally transverse rela- 

 tively stout and largely immersed veins. 



This species which was described by Engelhardt from 

 a single specimen collected at Potosi, Bolivia, was com- 

 pared with the existing Dalbergia riparia Bentham of the 

 Amazon Basin. It is not contained in my collections from 

 Potosi but three specimens were found at Corocoro, two 

 of which are complete to where the persistent calyx sepa- 

 rates the pod from its stipe. 



Comparisons with recent forms appear limited to the 

 Cynometreae of the Csesalpinaceae and the Dalbergiese of 

 the Papilionacese. The latter seems the most similar and 

 the two genera that invite the closest comparisons are 

 Dalbergia and Lonchocarpus. These comprise tropical 

 trees and shrubs, the latter often climbing, confined to 

 relatively low elevations, that is, usually found below 5000 

 feet. It is probably impossible to reach a decision in 

 regard to the proper genus in the case of isolated fossil 



