38 CLASS iv. ORDER IT, 



ELOPS, head smooth ; edges of the jaws and 

 palate rough, with teeth ; gill-membrane with 

 thirty rays, and armed on the outside in the mid- 

 ille with five teeth, 



ARGENTINA, teeth in the jaws and tongue ; gill- 

 membrane with eight rays ; vent near the tail ; 

 ventral fins many-rayed. 



ATHERINA, head somewhat flattened over the 

 upper jaw ; gill-membrane six-rayed ; body 

 marked by a silver lateral stripe. 



MUGIL, (mullet,) lips membranaceous ;. the in 

 ferior one carinated within ; teeth none ; at the 

 corners of the mouth an inflected callus; gill- 

 membrane with six curved rays ; body fleshy : 

 scales large ; dorsal-fins two. 



EXOCGETUS, (flying-fish,) head scaly ; jaws con- 

 nected on each side ; gill-membrane ten-rayed : 

 pectoral-fins very large, giving the power of fly- 



OLYNEMUS, head compressed, covered with 

 scales ; snout very obtuse and prominent ; gill- 

 membrane five or seven-rayed ; separate filaments 

 or setaceous processes near the base of the pecto- 

 ral-fins. 



CLUPEA, (herring, shad, sprat,) side-plates of 

 elre upper mandible serrated ; gill- membrane eight 

 rayed; gills internally setaceous; abdomen sharp^ 

 and serrated generally. 



CYPRINUS, (carp, tench, bream,) mouth small 

 and toothless; teeth in the throat; gill-membrane 

 three -rayed ; ventral-fins, in general, nine-rayed. 



MORMYRUS, snout produced ; mouth terminal j 

 teeth several, emarginated j. aperture without gill- 

 cover 5 gill-membraae single-rayed j body scaly, 



