PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 287 



Analysis of species of Hwviulon — Continued. 



00. Body elongate, the back not elevated, the depth 

 lees than length of head, 2.\ in body ; snout 

 very short, 3| in head; eye very large, 3; 

 maxillary 3^ in head, reaching little past 

 front of eye ; longest dorsal spine more than 

 half depth of body; anal low, its spines 

 small, the second 2f in head ; fins all yellow. 



T^NIATUM, 15. 



00. Dorsal spines 13; anal fin low; preorbital low ; gill-rakers ui moderate or rather 



large number, 12 to 18 on lower part of arch; 

 lower jaw not projecting ; mouth little ob- 

 lique ; body comparatively elongate, the 

 depth 2f to 3^ in length ; body with longi- 

 tudinal yellowish stripes; scales rather 

 small; size smaW^Bathy stoma). 



q. Month large, the maxillary reaching middle of 

 eye, its length about half head; gill-rakers 

 rather short and few ; scales moderate, 50 to 

 55 in the lateral line ; second anal spine 

 scarcely larger than third, 2f or more in 

 head. 



r. Body oblong, the back moderately elevated, the 

 depth 2f to 3 in length Rimator, 16. 



rr. Body eubfusiform, the back little elevated, the 

 depth 3J to 3i in length. 



AUROLINEATUM, 17. 



qq. Month rather small, the maxillary not reach- 

 ing to opposite middle of eye, its length not 

 quite half head; gill-rakers numerous, rather 

 long ; scales small, about 70 in lateral line ; 

 second anal spine notably longer than third, 

 more than f length of head; body more 

 elongate than in any other species, the depth 

 abont 3^ in length Quadrilineatum, 18. 



hh. Lower jaw projecting beyond upper ; gill-rakers comparatively long and 



slender, about 22 on lower part of anterior 

 arch (Lythrulon). 



t. Mouth small, very oblique, the maxillary reaching 



pupil, 2i in head ; head short, 3f in length ; 



snout very short, acute ; body rather deep ; 



' anal fin very low, its longest ray, when 



depressed, not nearly reaching middle of 

 last ray; second anal spine little longer 

 than third ; scales of back and sides each 

 with a pearly spot, these forming undu- 

 lating streaks Flavoguttatum, 19. 



«a. Scales above lateral line arranged in longitudinal series, which are throughout 



parallel with the lateral line ; dorsal spines' 

 13 (or 14) (Orthostcechus). 



