402 CONTRinUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 
{inal spines 3, rapidly graduated ; ventral fins abdominal, not far baelc, 
attaclieil to the elongate coracoid bone, composed of one spine and live 
rays; caudal forked. Air-bladder large, simple. Intestinal canal long, 
reritonenm nsnilly black. Vertebrie 24. Genera 3; species 70-80; 
inhabiting- the fresh waters and coasts of warm regions, feeding on 
organic matter contained in mnd. A considerable indigestible portion of 
the latter is swallowed, and in order to prevent larger bodies from pass- 
ing into the stomach, or substances from passing through the gill-open- 
ings, these lishes have the organs of the pharynx modilied into a 
liltering apparatus. They take in a quantity of sand or mnd, and 
after having worked it for some time between the pharyngeal bones, 
they eject the roughest and indigestible portion of it. TTie upper 
])haryngeals have a rather irregular form ; they are slightly arched, the 
eonv^exity being directed towards the pharyngeal cavity, tapering an- 
teriorly, and broad imsteriorly. They are coated with a thick, soft 
membrane, which reaches far beyond the margin of the bone, and is 
studded all over with minute horny cilia. Each branchial arch is i)ro- 
vided with a series of long gill-rakers, which are laterally bent down- 
wards, each series closely titting to the sides of the adjoining arch; 
they constitute together a sieve admirably adapted to permit a transit 
for the water, retaining at the same time every solid substance in the 
cavity of the pharynx. {Giinfher.) 
The AriigUldce, Attiermidcv, Sphyrwnidcv, and Ophiocephalidcc compose 
the group or suborder of Percesoces, thus characterized. Ventral tins 
abdominal; branchial arches well developed, the bones all present ex- 
cept the fourth superior branchihyal. Third sui^erior i)haryngeal much 
enlarged ; lower pharyngeal distinct. Scales cycloid. Pectorals ele- 
vated, about on a level with the upper i)osterior angle of operculum; 
spinous dorsal usually i^resent. (Latin, Perea, a i)erch; Psox, a pike — 
the group being intermediate in its imsition between the Percoids <aud 
the Raplomi.) 
(Mnijilicke Giintlier, iii, 409, 4G7.) 
* Jaws with a series of cilia, hut without true teeth ; part of the stomach muscular, 
gizzard-like MuGir, 195. 
195.— MUGIL LiDiisous. 
{Mullets.) 
(Artedi; Liumeus, Syst. Nat.: Mugil ceplialus L.) 
Body oblong, somewhat compressed, covered with large cycloid scales. 
Uead large, blimtish, convex above, scaled. Mouth small. Jaws tooth- 
