ON THE AMAZON. 195 
Tapajoz from the south, and of three small rivers from the north : the 
Surubiü, on which stands tlie village of Alemquer; and, higher up, the 
Cruá and the Mamurá, which divide the space between Alemquer and 
Obidos into three nearly equal portions. The triangular peninsula 
opposite Santarem, at the junction of the Tapajoz and Amazon, is 
constituted an island by a narrow /furo,* called Igarapé Assi, the 
mouths of which are indicated but not named in the French chart, 
The Rio Aripixuna, debouching into the large bay of the Rio Préto,+ 
above Santarem, becomes a furo in winter, by the waters of the 
Amazon entering from the north. At that season the Amazon, also, pours 
its waters into the same bay across the narrow isthmus at the mouth 
of the Lagoa Grande, and the island thus formed is called Parica-tüba. 
North of this is the main river, flowing through at least three wide and 
permanent channels ; the first is between the islands of Parica-tüba and 
Marimari-tába (the latter in reality two islands, with a narrow furo 
between them); the second is bounded on the north by the island of 
Arapixi; and the third (a very wide channel) has on the north a large 
island without name, at the mouth of the Surubiá. There is even a- 
fourth narrow channel of Amazon water between this island and the 
mainland, which must be traversed in order to reach the village of 
Alemquer. All these islands lie in a direct line between the Tapajoz 
and the Surubii, and there are several others to eastward and west- 
ward of them. 
Vessels ascending the river from Santarem generally pass to the north 
ward of the Ilha de Marimarituba, where the current runs less swiftly ; 
but we followed throughout the southern channel, or that laid down in 
the French chart. A very prominent and rather rocky point, known 
as the Punta de Paricatuba, is indicated but not named in this chart ; 
it is in long. 57° 10’ west from Paris. A little higher up (in long. 
57° 13’) is a small group of sitios called Goajara, but in the chart 
Coapiranga. The true Coapiranga is in long. 57° 15’, nearly in the 
centre of the bay, and opposite the southern extremity of the island 
of Marimarituba. . 
* Furo, from furar, to bore, a narrow channel between two islands, or through 
which the waters of a river pass from ahigher point to a lower. 
. $ Rio Préto, the Priests, or Black River, is the name uniformly applied here 
to the lower part of the Rio Tapajoz, whose clear waters run side by side with the 
muddy waters of the Amazon for miles ere they mingle. . s: 
2c2 
