NATURAL HISTORY. 
137 
ROOM IV.] 
The first group has the ventral fins under the pectorals, five soft rays to 
the ventral fin, and seven rays to the opercular membrane. Some of 
these have two dorsals, or the dorsal fin cut down to the base so as to 
look like two. The Perch {Perea) and allied genera have velvet-like 
teeth. The Pike-Perches {Lucio-Perca) have distinct canines; others 
have only a single undivided dorsal fin. Some of these have canine teeth, 
as the Serrani; others, as the Centropristes, have only velvet-like teeth. 
The Mcena have a very protractile mouth, and the teeth on the palate 
form a narrow band. The second group also have the ventral under 
the pectoral, five soft rays to the ventral, but they have fewer than seven 
rays to the opercular membrane, as the genera Pomotis, Centrarchus , 
Trichodon, Priacanthus. The third group are peculiar for having only 
five soft rays to the ventral, they have the ventral under the pectoral, 
more than seven rays to the opercular membrane, and only a single 
dorsal; their scales are very rough and strong, as the genera Myripristes, 
Holocentrum , Beryx, Monocentris. The fourth group have the ventral 
before the base of the pectoral, as the genus Percophis, which have 
canines mixed with the other teeth. The rest have only velvet-like teeth, 
as Percis, and Pinguipes. The Peralepis have the ventral fins placed 
behind the base of the pectorals; they have only a very small dorsal fin, 
like a fat fin. 
The family of Mullus (Mullid^l) have many of the characters of the 
Perch, but they have two small distant dorsals, and their operculum 
covered wdth large deciduous scales; their operculum is not toothed, and 
they have tw o beards from the chin, as the Mullus and Upeneis. 
The family of the Scienoids (Schlnid^e) are of the same form as 
the Perches; they have their preoperculum generally toothed or 
spinous ; their jaws are slightly protractile, and they have no teeth on 
the vomer nor palate. Some have on the edge of the lower jaw a 
beard, they have also distinct dorsal fins. The Umbranes have only 
one beard, and the Lonchurus has two on the middle of the chin. 
The Pagonias have many bands in a row across the low r er jaw, 
and the Micropogons some very small beards on the end of the lower 
jaw. Most have the chin destitute of beards; some s of them have 
two dorsal fins, or the dorsal so deeply cut in as to make it appear two. 
The preoperculum is not denticulated, and the teeth nearly equal, as in 
Nebris , Elegenis. In others the preoperculum is strongly denticulated 
and the teeth are nearly equal. Some of them have the muzzle 
swollen, as the Maigre, Leiostomus , and Eques. Others have a 
simply rounded muzzle, as the Larinus and Lepipterus . Borideus 
and Cenodon differ from the former by having large blunt teeth in 
the jaw r s. The tw 7 o following genera differ from the preceding in 
being furnished with strong prominent canine teeth, as Otolithus, 
Ancylodon. The rest of the Scienoids have only a single dorsal 
fin; some have as many as seven rays to the gill membrane. The 
Hemulons have a pit and two small pores under the chin, and the 
vertical fins scaly. The Pristinomes have the same pores as the 
former, but the fins are not scaly, and the Diagrames have four or six 
pores under the chin. Others have, as is generally the case with other 
fishes, only five or six rays to the gill membrane, the lateral line 
is continued to the tail. The Lobotes have a short muzzle, the 
