272 FISHES. 



of ten or eleven rays; teeth 2, 4-4, 2, with 

 masticatory surface. . LYTHRUIIUS, 16. 



kkk. Scales rather large, not closely imbricated, 

 brilliantly silvery; lat. 1. 35 to 40; fins un- 

 spotted, uncolored; forehead, etc., rosy in 

 spring : anal fin rather long, of nine to twelve 

 rays; body elongate ; teeth (inner series) 4-4, 

 usually without masticatory surface. 



MINNILUS, 20. 



jj. Dorsal directly above ventrals (rarely slightly pos- 

 terior) ; anal short, of eight or nine rays. 

 I. Lateral line with less than 45 scales. 



m. Scales quite large, closely imbricated, the ex- 

 posed portion being much higher than long, 

 especially on the sides of the body, very 

 conspicuously so in adults; body corn- 

 pressed; lateral line decurved; mouth 

 oblique ; males with the head tuberculate 

 in spring. 



Dorsal fin directly over ventrals, without 



distinct black spot ; sides and fins with 

 red pigment in spring ; mouth and eyes 

 large; anal commonly I, 9; teeth 2, 

 4-4, 2 with masticatory surface. 



LUXILUS, 17. 



Dorsal fin slightly behind ventrals, with 



a large black blotch behind ; pigment 

 on sides and fins pure satin white; 

 mouth and eyes rather small ; A. nor- 

 mally I, 8; teeth 1, 4-4, 1, sometimes 

 crenate. . . PLARGYRUS, 18. 

 mm. Scales normal, not closely imbricated. 

 n. Elongated, compressed species with the 

 mouth very oblique, and the lower jaw 

 usually projecting; scales generally bril- 

 liantly silvery; eye large; lateral line 35 

 to 40; inner row of teeth 4-4, without 

 masticatory surface. r PHOTOGENIS, 19. 



