May, igo2. Thk Icniinoi.ocjv ok Mexicd — Meek. hi 



<:;■. Anal vslys 17; gill-rakers 4-f-2i = 25; scales 48-12; body light, 

 translucent, slightly compressed; depth 5^. Origin of spinous dorsal 

 slightly nearer tip of snout than base of caudal. p.A.'rzcu.vRO. 



.i,X. Anal rays 13 or 14; gill-rakers ^-\-iyz=2i; scales 54-12. 

 Body dark, opaque, scarcely compressed; depth 6}^; origin of spinous 

 dorsal nearer tip of snout than base of caudal by a distance greater 

 than diameter of eye. zirahuex. 



/f. Origin of spinous dorsal midway between base of caudal fin 

 and anterior margin of the orbit, or the nostril; anal rays 17 to ig; 

 scales 54-15; gill-rakers 4-1-15 = 19. Species of large size. 



HUMBOLD'l'IANU.M. 



('c\ Scales with crenate edges; origin of spinous dorsal nearer 

 base of caudal than tip of the snout; anal rays 18 to 24. i^Lcthosiole.) 



h. Snout short, 3^ in length of the head, being equal to or 

 shorter than the diameter of the eye. Species of small size. 



/. Scales in lateral series 49, transverse 13: anal base equals the 

 length of the head, its rays 21. CHAPAi^yE. 



//. Scales in the lateral series 62, transverse 14: base of anal fin 

 \\ in the length of the head, its rays 19. graxdocule, 



lih. Snout long, '2.\\.o 2| in the length of the head; diameter of eye 

 4.V to 5f in head. Species of large size. 



/'. Upper jaw decidedly longer than the lower, mandible i\ in 

 the head: tip of snout black; base of anal fin i\ in the head, its rays 

 19 or 20; scales 53 to 56-15: teeth large, not in definite rows: snout Q.\ 

 in head: diameter of eye 5|: gill-rakers 5-j-i9. i'Ro.melas. 



kk. Lower jaw decidedly longer than the upper: mandible i i to 

 2i in the head: tip of jaws not black (dusky in some specimens). 



/. Scales between dorsal fins very small, more than 20 in a 

 series between the fins; scales 60 to 70-22: gill-rakers ?-|-23; teeth 

 large anteriorly, canine-like, not arranged in definite rows: mandible 

 2 in head. sphr/Ena. 



//. Scales in the region of dorsal fins hirger, fewer than 15 in a 

 series between the two fins. 



///. Scales in the lateral series 54 to 60. 



;;. Lower jaw projecting but little beyond tlK- upper mandible, 

 about i\ in head. 



o. Teeth weak, in patches, not arranged in definite rows; gill- 

 rakers 4-I-23: scales 56 to 60-18; mandible 2^- in head. Lucius. 



00. Teeth large and strong, in two definite rows, the larger teeth 

 on inner row of upper jaw and outer row on lower; mandible 2I in 

 head; gill-rakers 54-20; scales 58-20. lerm^e. 



nn. Lower jaw projecting much beyond the upper, mandible li 



