578 TELEOSTEI CHAP. 
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 Hrythrinus 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 Yenocharaz 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 
Fie. 350.—Hydrocyon goliath, from the Congo. 5 nat. 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 ” (Servrasalmo) 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 
orbignianus, 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. 
