1866.] DR. A. GUNTHER ON THE FISHES OF PANAMA. 603 



Neetroplus, g. n. 



Differing from Heros in having a front series of flat incisor-like 

 teeth. 



Neetroplus nematopus. 

 D 15 A 8 



From Lake Managua. 



PlMELODUS MANAGUENSIS. 



D. 1/6. A. 14-15. P. 1/9. 



Adipose fin rather more than one-third of the total length (without 

 caudal) ; maxillary barbels extending nearly to the base of the dorsal 

 fin. Dorsal spine very feeble ; anal rays not nearly extending to the 

 end of the adipose fin, if laid backwards. 



Lake Managua. 



Ch.etostomus aspidolepis. 



L. lat. 25. 



Diameter of the orbit one-third of the width of the interorbital 

 space. Interoperculum with very few short spines. Seven scutes 

 between the two dorsal fins, twelve between anal and caudal. 



Pristigaster macrops. 

 D. 13. A. 61. L. lat. 53. 



Greatest depth of the body one-third of the total length (without 

 caudal). Eye one-third of the length of the head. Origin of dorsal 

 midway between caudal and scapula. 



Panama. 



Pristigaster argenteus. 

 D. 11. A. 56. L. lat. 51. 



Greatest depth of the body two-sevenths of the total length. Eye 

 two-sevenths of the length of the head. Origin of dorsal much 

 nearer to caudal than to scapula. 



Panama. 



Meletta petenensis. 



D. 14-15. A. 20-23. L. lat. 40. 



Distinguished from M. thrissa by its larger head, the length of 

 which is two-sevenths of the total (without caudal). 

 Lake Peten. 



Meletta libertatis. 



D. 17. A. 19. L. lat. 48. 



The length of the head is contained thrice and two-thirds in the 



