]48 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.54. 



from Potosi there is some resemblance to Platypodium potosianum 

 Engelhardt, which is about the same size but generally wider with 

 fewer regularly curved camptodrome secondaries. There is also a 

 more distant resemblance to Cassia wendtii Britton, which is more 

 inequilateral, with a shorter petiolule, fewer and better marked 

 camptodrome secondaries, generally more pointed tip and widest 

 below the middle. Named for the collector, Prof. B. L. Miller, of 

 Lehigh University. 

 Holotype.—C&t. No. 35104, U.S.N.M. 



Genus DALBERGIA Linnaeus (son). 



DALBERGIA POTOSIANA, new species. 



Plate 17, fig. 8. 



Description. — Leaflets sessile, obovate in general outhne, with a 

 broadly rounded deeply emarginate apex and a broadly cuneate base. 

 Margins full, entire. Leaf substance thin but firm. Length, about 

 1.5 cm. Maximum width, above the middle, about 5 mm. Midrib 

 very stout, curved. Secondaries very thin, about three to five 

 camptodrome pairs. Tertiaries mostly obsolete. Areolation fine, its 

 details obscure. 



This well-marked species is clearly distinct from the other members 

 of the Potosi flora and not close to Dalhergia chartacea Engelhardt, 

 which has larger, ovate leaflets. It is very similar to a large number 

 of existing and fossil species of Dalhergia, to which a large number of 

 fossil leaflets and pods have been referred. A pod from Potosi is 

 referred to this genus by Engelhardt, but its determination is not 

 above suspicion. 



The existing species of Dalhergia nimiber about 80 forms, occurring 

 in both the Oriental and Occidental Tropics. There are a lai^e num- 

 ber of species in the Amazon Basin. 



Holotype.— Cat. No. 35105, U.S.N.M. 



DALGERGIA CHARTACEA Engelhardt. 



Dalhergia chartacea Engelhardt, Sitz. Naturw. Gesell. Isis in Dresden, 1894, 

 Abh. 1, p. 8, pi. 1, fig. 25. 



Description. — Leaflets ovate, bluntly pointed at the apex, with a 

 broadly cuneate base, nearly equilateral, with full and evenly rounded 

 entire margins. Texture coriaceous. Length, about 2.5 cm. Maxi- 

 mum width, midway between the apex and the base, about 11 mm. 

 Midrib straight and mediumly stout. Secondaries thin; about six 

 pairs diverge from the midrib at angles of about 45°; they range 

 from opposite to alternate and pursue a subparallel camptodrome 

 course. Tertiaries mostly obsolete. 



This somewhat doubtfully determined form is not represented in 

 the present collections. It was compared by Engelhardt with the 



