SS GLASS IV. ORDER IY. 
- EiLops, head smooth ; edges of the jaws and 
palate rough, with teeth; gill-membrane with 
thirty rays, and armed on the outside in the mid- 
dle 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. 
Muei., (mullet,) ips membranaceous ; the in- 
ferlor 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. 
Exocerus, (flying-fish,) head scaly ; jaws con- 
nected on each side; gill-membrane ten-rayed : 
pectoral-fins very large, giving the power of fly- 
ing. 
2 aati 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 pecte- 
ral-fins. | 
Cuiupra, (herring, shad, sprat,) side-plates of 
the 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. 
Mormyrvus, snout produced ; mouth terminal ; 
teeth several, emarginated ; aperture without gill- 
cover; gill-membrane single-rayed ; body scaly. 
