THE WATER-OPOSSUMS, 223 
toa large Rat, is a comparatively rare animal inhabiting the 
rivers of Brazil, and living chiefly or exclusively on crustaceans 
and insects. Although very little is known of its habits, it 
would appear from the circumstance that a specimen was taken 
in a basket-trap similar to those used for catching eels in 
Europe, that the creature is an expert diver. Small fish 
doubtless also form a portion of its diet. The female has a 
well-developed pouch, in which the young, usually five in 
number, are carried for some time; and it will be obvious 
that during that period the creature must refrain from entering 
the water. Later on, the young accompany their parent to the 
river. and are exercised by her in swimming and diving, 
