MOON EYE AND CHISEL JAW 2853 



the arapaima is captured by the natives of Brazil with a hook and line; its flesh be- 

 ing highly esteemed as food, and in a salted condition largely exported. It is also 

 taken by being struck with an arrow, to which a line is attached; and a graphic 

 account of this method of hunting is given by Schomburgk. It appears that a party 

 go out in a boat, and row about until a fish is sighted, when the bow and arrow are 

 brought into requisition, and if the shot be successful, the monster is at length 

 landed. 



The four representatives of the typical genus Osteoglossum may be 

 distinguished from the last by the presence of a pair of barbels to the 

 lower jaw, the obliquity of the cleft of the mouth, the sharp lower 

 surface of the body, and the greater length of the pectoral fins. Of the four spe- 

 cies the first is American, and has the same distribution as the true arapaima, the 

 second occurs in Sumatra and Borneo, while the other two are Australian. The 

 two latter have, however, but a very local distribution, the one (O. leichardti} being 

 confined to the rivers of Queensland, where it is known to the natives as the barra- 

 mundi, and to the colonists as the Dawson river salmon; while the second (O. 

 jardinei], which is distinguished by the absence of a spine to the anal fin, inhabits 

 the rivers discharging into the gulf of Carpentaria. The flesh of both these species 

 is highly esteemed as an article of food. 



The third genus of the family, which includes only a single species 

 M th d (H eter ti s nilotica), differs from both the foregoing in having the 

 Arapaima pharyngeal bones numerically the same as in the southern pikelets, on 

 which account Professor Cope regards it as the type of a distinct 

 family. Differing from the other two genera in the comparatively small size of the 

 cleft of the mouth, and also in the approximate equality of the length of the jaws, 

 this fish has no barbels, and only a single series of teeth in the jaws, teeth being 

 also present on the pterygoid and hyoid bones, but wanting on the vomer and pala- 

 tines. A further peculiarity is to be found in the presence of a peculiar spiral 

 organ on the fourth gill arch; and the air bladder differs from that of the other 

 members of the family in its cellular structure, while the stomach comprises a mem- 

 branous and a muscular portion. The fish in question is found alike in the upper 

 Nile and in the rivers of Western Africa. It grows to about two feet in length. 



MOON EYE AND CHISEL JAW Families HTODONTID^E and 



PA N TOD ON TID^tt 



Each of the two fishes figured in the annexed illustration is the only represent- 

 ative not only of a genus, but likewise of a separate family; these families agreeing 

 with all the remaining ones of the present section in having the pterotic bone nor- 

 mal, the base of the skull double, and four- upper pharyngeal bones, all of which 

 are distinct, and the third the largest and directed forward. In the first family the 

 parietal bones are united, and there are two true tail vertebrae in front of the com- 

 p 1 ex bone supporting the rays of the caudal fin. 



