2842 



THE BONY FISHES AND GANOIDS 



family distinguished from the preceding by the absence of teeth on the pharyngeal 

 bones, and by the elongated air bladder being undivided, barbels being wanting. 

 While the figured species is from the west coast, the other (K. spekei) inhabits 

 Central Africa. 



THE CHARACINOID FISHES Family ERTTHRlNIDsE 



As an example of a very extensive family of fresh-water fishes, confined to 

 tropical America and Africa south of the Sahara, we select an American form 

 known as the piraya (Serrasalmo piraya), since in our limited space it is quite 

 impossible to deal with any of the others. It may be mentioned, in the first place, 

 that these fishes are common^ known as the Characinida , but as there is no such 



THE PIRAYA. 



(One-fourth natural size.) 



genus as the Characinus, it is obvious that this term cannot stand, and we have 

 accordingly adopted another. According to Professor Cope's arrangement, these 

 fishes belong to the same sectional group as the carp tribe, from which they may be 

 distinguished by the brain case not being produced between the orbits, and likewise 

 by the number of upper pharyngeal bones varying from four to one instead of being 

 always two; a further point of difference occurring in the structure of the upper 

 jaw, which is formed in front by the premaxillse, and at the sides by the maxillae. 

 Like the carps, the body is scaled and the head naked; but barbels are invariably 

 wanting, and the jaws may be either toothless, or furnished with a detention of a 

 very powerful type. In most cases there is a small fatty fin behind the dorsal; the 

 air bladder is always transversely divided into halves, and there are no false gills. 



