578 TELEOSTEI 



The air-bladder is divided into an anterior and a posterior 

 part by a constriction ; the posterior part is the longer, and its 

 anterior portion is cellular in Erytlirinus and Lebiasina. Pyloric 

 appendages to the stomach, which are constantly absent in the 

 Cyprinids, are more or less numerous. An. accessory respiratory 

 organ in a diverticulum above the fourth branchial arch has 

 been observed in Xenocharax and Citharinus. 



The appearance and habits of the genera which compose this 

 family vary greatly. Some resemble the Cyprinids and are 

 mainly vegetarians, whilst others recall Salmonids and Pike. 

 Among the most formidable are Hydrocyon, the Dogs of the Water, 

 or Kelb-el-Bahr of the Arabs, with their powerful jaws with 



FIG. 35Q.ffydrocyon goliath, from the Congo. T a ff iiat. size. 



shark-like teeth, visible when the mouth is closed, and which grow 

 to the size of the Salmon. The five known species inhabit the Nile 

 and the rivers and lakes of tropical Africa. No less ferocious are 

 the " Piranha " or " Cariba " (Serrasalmo) of South America, whose 

 bite has been compared to the cut of a razor. They abound in 

 some rivers and are much dreaded by people having to enter the 

 water, as they fiercely bite off big pieces of flesh as with a pair 

 of scissors, and the smell of blood is said to attract them by 

 thousands ; they show a great tenacity of life and can remain for 

 hours out of the water. Serrasalmo niger has been observed by 

 Schomburgk to produce a grunting noise in the water. Salminus 

 or'bignianus, of the Plate River, " Dorado " of the Spaniards, which 

 reaches a length of 3 feet, has the predacious habits of the Pike, 

 and follows other fishes moving in shoals ; its flesh is much valued, 

 although very full of bones, like that of all-Characinids. 



