DOWN THE RIO NEGRO 495 
Diplotropis nitida (Fabacese) was one of the commonest trees 
of the gap6 all the way down to Barra. When I started it was 
in full flower; it had flowered also in September. On nearing 
the Barra there was another burst of flower. At the first flowering 
many of the panicle-s are only in bud ; these open later. Dicorynea 
Spruceana (near Cassia) was almost equally frequent as far down 
as the mouth of the Rio Branco. 
Lecythis amara occurred also all the way down, but the great 
country of this group seems to be from the mouth of the Maraivia 
(above Sta. Isabel) to that of the Rio Negro, especiaUy on the 
south bank and on the islands. 
The fine new genus Henriquezia was seen all the way down 
where the soil was rich. It was in flower and very ornamental. 
Drepanocarpus (Fabaceae) was also abundant all the way from the 
mouth of the Casiquiari to that of the Rio Branco and on to 
near the Barra. It was conspicuous from its whitish lunate pods 
hanging in bunches from the free portion of the stems that spring 
in graceful arches from the sides or summit of the forest wall. 
There are two species of the genus, differing in the number of the 
leaflets. 
On a steeply sloping bank above Cabuqueno were several 
trees I did not know — some of them in flower and fruit. A little 
below Barcellos, and especially about Airao, we saw the Castan- 
heiro (Brazil-nut tree) frequently, on ground that rises from the 
river and stretches away into a low hill. This tree is remarkable 
for its trunk rising naked above the surrounding forest, like the 
Samauma, but it has a flatter-topped crown, easily distinguished 
from the hemispherical dome of the Silk-cotton trees. 
[During his enforced stay in Barra waiting for 
the steamer to take him up to Peru, Spruce made 
a few botanical excursions, the most interesting 
being to a stream which enters the Rio Negro some 
fifteen miles above the city, and has on it what is 
said to be the highest waterfall in the whole district. 
His account of this visit, slightly condensed, is as 
follows : — ] 
Excursion from Barra, February 12, 1855, 
TO THE Rio Taruma 
This small river enters the Rio Negro about five 
hours' rowing above the city, where the coast bends 
