272 FISHES. 



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

 masticatory surface. . LYTHRURUS, 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. 



ra. 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 com 

 pressed; lateral line clecurved; 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. . PHOTOGENIS, 19. 



