Eigenmann: The Serrasalmin.e and Mylin,^. 227 



two small graduate cusps on each side of the large median cusp. 

 In the other genera the teeth of one or both jaws are asymmetric, 

 the cutting edge of one side longer than on the other, and the cusps, 

 if present, not bilaterally symmetric. 



In the species of Serrasalminje, aside from Pygopristis, there is a 

 complete gradation from slender, sharp-snouted, narrow-headed 

 species with highly developed teeth on the palate, like Serrasalmo 

 elongatus, to deeper, broad-headed, bull-dog-nosed species with the 

 palatine teeth indifferently developed, or, in some species absent 

 {Pygocentrus piraya, Rooseveltiella nattereri, etc.). One of the broad - 

 headed species has the adipose fin rayed, and has been separated as 

 representing a distinct genus, Pygocentrus. 



All of the species of the Serrasalminae have an evil reputation as 

 carnivores. Those with a short upper jaw, heavy lower jaw, broad 

 interorbital, and no palatine dentition, and which are known as peri, 

 pirays, or piranhas (species of Pygocentrus and Rooseveltiella) are 

 undoubtedly the worst. Stories of their depredations, from cutting 

 the leaders of fish-lines, cutting up fish-nets, mutilating other fishes, 

 taking off fingers or toes, or otherwise mutilating man or beast, to 

 skeletonizing a horse and rider, who tried crossing a stream where 

 they abound, are found in many books of travel, from that of Fray 

 Pedro Simon in 1535 to that of Colonel Theodore Roosevelt in 1914. 

 Credulity and "fear of the unseen terror" have undoubtedly exag- 

 gerated the real conditions, but it is certain t*" ''n some regions where 

 they are excessively numerous they are it nuisance. Mr. 



Anisits, who collected fishes for me in the up[, . araguay, reported 

 that at one point he did not succeed in doing much, because the 

 piranhas cut up the nets to such an extent that it required hours to 

 patch them after every cast, and it was dangerous to life to enter the 

 water. 



Humboldt in his Observations, Zoologie, II, 1809, p. 174, quotes 

 from two old sources as follows: 



"Llevaron algunos de los soldados de Herera (mas arriba de Cab- 

 ruta) unas calzas enteras de red con muy gruessos nudos, que se hal- 

 laron entre el demas pillaxe de aquella gente, que usaran dellas los 

 Indios para entrar a pescar en las cienegas, con que se defendian de 

 unos peces que los Espaiioles llamaron Caribes, por ser tan fieros y 

 atrevidos que hacen en todo lo que topan dentro del agua: y assiendo 

 destos nudos quando entraran los pescadores a pescar, quedaba libre 



