66 CHECK LIST OF THE 



falciform. No interclavicles. Mouth with teeth. Air bladder with a dis- 

 tinct duct. Ventral fins abdominal, rarely wanting ; pectoral fins placed 

 low; dorsal fin more or less posterior, the first ray occasionally stiffened 

 and spine-like; no adipose fin. Head usually covered with scales, like 

 those on the body. Species chiefly inhabiting fresh water. 



FAMILY UMBRID^E. (MuD MINNOWS.) 



Body oblong, broad anteriorly, compressed behind. Head large, 

 flattened above. Mouth moderate, with bands of villiform or cardiform 

 teeth on premaxillaries, lower jaw, vomer, and palatines ; premaxillaries 

 not protractile ; lateral margin of upper jaw, formed by the broad, short, 

 maxillaries, which are toothless and without distinct supplemental 

 bone ; lower jaw the longer. Gill openings wide, the membranes scarcely 

 connected ; gill rakers little developed ; branchiostegals six to eight. 

 Scales moderate, cycloid, covering head and body; lateral line wanting. 

 Dorsal fin moderate, posterior, in advance of anal ; ventrals small, close 

 to anal ; pectorals inserted low ; caudal fin rounded. Stomach without 

 blind sac ; no pyloric caeca ; pseudobranchise hidden, glandular ; air 

 bladder simple. Oviparous fishes, the sexes similar. Carnivorous fishes 

 of small size, living in mud, or among weeds, at the bottom of clear, 

 sluggish streams and ponds ; extremely tenacious of life. 



GENUS UMBRA. (MUDFISHES.) 



Body oblong, covered with cycloid scales of moderate size, without 

 radiating striae ; no lateral line ; head shortish, little depressed ; eye rather 

 small ; cleft of mouth moderate ; ventral fins six-rayed, below or slightly 

 in front of dorsal ; anal fin much shorter than dorsal ; pectorals rather 

 narrow, rounded, placed low, with twelve to fifteen rays, which are much 

 articulated ; caudal rounded ; preopercle and preorbital with mucous pores ; 

 branchiostegals six; gill rakers rather short, thick. Size small. 



SUBGENUS MELANURA. 



Mud Minnow. ( Umbra limi. ) 



(74) Mud Minnow. Dogfish. . 



(Umbra limi.) 



Body comparatively short and stout. Head rather large, flattened 

 above. Ventral fins slightly before dorsal ; anal much smaller than dorsal. 



