318 



NATURAL HISTORY. 



snout, is divided into two halves, right and left, and, says Dr. Giinther, 

 '.' seems to have lost its function of vision, and assumed that of produc- 

 ing light." In regard to all these forms there remains yet much to be 

 learned. Our figure shows one very peculiar species from the deep seas. 

 The largest strictly fresh-water fish known is the periecu of the Amazon 

 and its tributaries. It is said to reach a length of fifteen feet, and a weight 

 of over four hundred pounds. It is very important in the region where it 

 occurs, and is stated to form the main article of animal food for half the 



Fig. 302. —Deep-sea fish. 



inhabitants of the province of Para. Observations upon its habits are few. 

 Mr. W. H. Edwards speaks of it as follows : " Not long after noon we 

 stopped at a house (on the Amazon), where a number of Indians were col- 

 lected about a periecu, which they had just caught. This was the fish 

 whose dried slabs had been our main diet for the last few weeks, and we 

 embraced the opportunity to take a good look at so useful a species. He 

 was about six feet long, with a large head and wide mouth, and his thick 

 scales, large as dollars, were beautifully shaded with flesh-color. These 

 fish often attain a greater size, and, at certain seasons, are very abundant, 



