402 CONTRTBUrrOXS to north AMERICAX ichthyology IV. 



anal spines 3, rapidly graduatefl ; ventral fins abdominal, not fiir back, 

 attached to the elongate coracoid bone, composed of one spine and five 

 rays; caudal f()rli;ed. Air-bladder large, simple. Intestinal canal long. 

 Peritoneum usually black. Vertebra3 24. Genera 3; species 70-80; 

 iuhabitiug the fresh waters and coasts of warm regions, feeding on 

 organic matter contained in mud. 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 fishes have the organs of the pharynx modified into a 

 filtering apparatus. They take in a quantity' of sand or mud, and 

 after having worked it for some time between the pharyngeal bones, 

 they eject the roughest and indigestible portion of it. The upper 

 pharyngeals have a rather irregular form; they are slightly arched, the 

 convexity being directed towards the pharyngeal cavity, tapering an- 

 teriorly, and broad posteriorly. They are coated with a thick, soft 

 membrane, which reaches far beyond the margin of the bone, and is 

 studded all over with minute hornj' cilia. Each branchial arch is i)ro- 

 vided with a series of long gill-rakers, which are laterally bent down- 

 wards, each series closely fitting 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. {Gunther.) 



The MugllidaB, Atlierinidw, ^phyrwnidw, and OpMocephaUdw compose 

 the group or suborder of Percesoces, thus characterized. Ventral fins 

 abdominal ; branchial arches well developed, the bones all present ex- 

 cept the fourth superior branchihyal. Third superior pharyngeal much 

 enlarged ; lower pharyngeal distinct. Scales cycloid. Pectorals ele- 

 vated, about on a level with the upper posterior angle of operculum; 

 spinous dorsal usually present. (Latin, Perca^ a perch ; Esox,, a pike — 

 the group being intermediate in its position between the Percoids and 

 the Haplomi.) 



(MiigUidw Giintber, iii, 409, 4G7.) 



* Jaws with a series of cilia, but without true teeth ; part of the stomach muscular, 

 gizzard-like -- MuGil-, 195. 



19-5.— M TOIL Liuu.neus. 



{Mullets.) 



(Artedi; Liuuaius, Syst. Nat. : type Mugil cejjhalus L.) 



Body oblong, somewhat compressed, covered with large cycloid scales. 

 Head large, bluntish, convex above, scaled. Mouth small. Jaws tooth- 



