194 MR. SPRUCE'S BOTANICAL EXCURSION 
Amazon and of the Trombétas, It may be the Panicum elephantipes 
of Martius. ; 
At about half the distance between Santarem and Obidos, opposite 
the Ilha de Marimarituba, there is a break in the cacoals. The river 
here makes a wide curve to the southward, and the shore is lofty— 
often 200 feet high—and sometimes rocky. This we found a better 
field : it afforded us a fine Rubiaceous shrub, conspicuous from afar by 
its brilliant scarlet bracteas, a twining Bignoniacea, with large panicles 
of violet-coloured flowers, some Ferns, &c. Into this bay are two 
communications with the Lagoa Grande de -Villa Franca, through 
which the waters of the latter enter the Amazon. About thirty miles 
above Obidos there is another channel, by which the waters of 
the Amazon pass into the lake ; and in the rainy season there are three 
other small igarapés lower down, affording a similar passage to the 
waters of the river. A large portion of the Amazon water thus flows 
through the lake, and it is, therefore, incorrect to say that the channel 
at Obidos is the whole breadth of the Amazon, and consequently 
(being only two miles wide) its narrowest part. The Lagoa Grande 
seems to have been visited by no traveller; yet it is one of the largest 
lakes in South America, being from forty-five to fifty miles long from 
east to west, and at least twelve miles broad. The greatest breadth 
is nearly opposite Obidos. The village of Villa Franca is near its 
eastern extremity. Its waters are stated to abound in fish, and especially 
to contain a small species of turtle not found elsewhere. On the flat 
shores there are now numerous fazendas of cattle and cacao. 
During our long voyage, and previously at Santarem, I had oppor- 
tunities for testing the accuracy of the French Survey of this part of 
the Amazon, made by M. Tardy de Montravel, in the brig Boulonnaise, 
in the year 1844, The principal points appear correctly laid down, but, 
as might be expected from the short time employed in the survey, the 
details are very imperfect. Great obstructions seem to have been 
thrown in the way of the expedition by the local authorities ; and when 
its Commander wished to ascend the river a second time, in order to 
correct and complete his survey, he was actually denied permission! 
The Amazon, opposite Santarem, as laid down in the French chart, is 
only one of the channels of the river, there being several others with 
. intervening large islands, which may be considered as belonging to 
deltas formed by the junction with the Amazon of the large river 
