1. MACRODON. 281 



First Group. ERYTHRININA. 



Characiiiidse without adipose fin. 



South America. 



1. MACROLON*. 



Macrodon, M'dll. ^- Trosch. Ilur. Ichthi/ol. iii. p. 6. 



Dorsal fin placed nearly in the middle of the body ; adipose fin 

 none ; anal rather short ; ventrals below the dorsal. Body oblong, 

 covered with large scales ; head longish, wth the cleft of the month 

 wide. Cheeks covered with the enlarged infraorbital bones ; supra- 

 temporal plate single. Both jaws armed with a single series of conical 

 teeth, some being enlarged canine teeth. A band of viUiform teeth 

 on each side of the palate, each band with an outer series of larger 

 conical teeth and with a detached anterior patch of small \-illiform 

 teeth. Air-bladder -without cellular portion. 



Tropical America. 



1. Macrodon trahira. 



Tareira, Marcgr. p. 157. 



Esox nialabaricus, Bloch, tab. 392. 



SjTiodus nialabaricus, Bl. Schn. p. 397. 



tareira, Bl. Schn. p. 398. pi. 79 (very bad). 



Erj'tbrinus macrodon, Agass. in SpLr, Pkc. Bras. p. 43. 



trahira, Sjnx, I. c. tab. 18. 



brasiliensis, Spix, I. c. p. 45. tab. 20. 



Macrodon trahira. Mull. ^- Trosch. Hor. Ichth. iii. p. 6. tab. 3. fig. 2. 



: tareira, Cuv. <§• Veil. xix. p. 508. 



? Macrodon ferox, Gill, Ann. Lye. Nat. Hist. New York, \\. p. 411. 



D. 14. A. 10-11. V. 8. L.lat. 38-39. Vert. 26/10. 



Twelve longitudinal series of scales across the back, in front of the 

 dorsal fin, from one lateral line to the other ; nine across the back of 

 the tail. 



This species shows slight variations in the form of the body and 

 of the head, chiefly dependent on age and sex, which may induce 

 naturaUsts who have only a few specimens for examination to con- 

 sider them as specific. It is also very remarkable that some speci- 

 mens have large patches of asperities on the tongue, whilst others, 

 which perfectly agree with the former in every detail, have the 

 tongue smooth. Agassiz has counted from forty to forty-two scales 

 in a longitudinal scries ; but probably he has taken one of the series 

 above the true lateral line, which have more scales than the latter. 



Guianas, Brazil. 

 a, b, c-d. Adult and half-grown. British Guiana. 



* 1. Macrodon auritus, C. 8( V. xix. p. 519. — Montevideo. 



2. patana, C. S\ V. six. p. 522. — Cayenne. 



3. guavina, Valcnc. in Humb. Ohscrv. Zool. ii. p. 179. tab. 48. fig. 1. 



(bad) ; C. i( V. xix. p. 527 ; Sir W. Jardine in Schomb. Fish. Brit. 

 Guiana, ii. p. 207. pi. 29 (cop. Humh.). — Lake of Tacarigua. 



4. Erytlirinus microcephaliis, Agass. in Spix, Pise. Bras. p. 44. — Rio S. 



Francisco. 



5. Macrodon teres. Cuv. ^- Val. six. p. 521. — Lake of Maracaibo. 



