466 
ZOOLOGY OF 
shows its back above water, only rising to breathe, 
which it does by protruding its nostrils almost imper- 
I 
ceptibly above the surface: the. Indian’s keen eyes per- 
ceive this, even at a considerable distance ; but an arrow 
shot obliquely would glance off the smooth flat shell, so 
he shoots up into the air with such accurate judgment, 
that the arrow falls nearly vertically upon the shell, 
which it penetrates, and remains securely fixed in the 
turtle’s back. The head of the arrow fits loosely on to 
the shaft, and is connected with it by a long fine cord, 
carefully wound round it ; as the turtle dives, they se- 
parate, the light shaft forming a float or buoy, which the 
Indian secures, and by the attached cord draws the 
prize up into his canoe. In this manner almost all the 
turtles sold in the cities have been procured, and the 
little square vertical hole of the arrow-head may gene- 
rally be seen in the shell. 
Besides the great tataruga {Podocnemis expansd), there 
are several smaller kinds, also much used for food. The 
Tracaxa (Pmys tracaxa, Spix) and the Cabe^udo [P, ma- 
crocephala, Spix) have been described by the French 
naturalists, DumM and Bibron, as one species, under 
the name of PeltocepJialus tracaxa ; but they are quite 
distinct, and though their characters are perhaps not 
easy to define, they could never be confounded by any 
one who had examined them in the living state. They 
are found too in different localities. The tracaxa is 
abundant in the Amazon, in the Orinooko, and in the 
Guaviare, all white-water rivers, and very scarce in the 
Rio Negro. The cabegudo is very abundant in the Rio 
Negro and in the Atabapo, but is not found in the 
