UMBRA MUDFISHES 203 



Fishes of small size and carnivorous habit, inhabiting 

 muddy weedy bottoms of fresh-water streams and ponds; very 

 tenacious of life. One genus, with three species, one European 

 and two American, one of the latter inhabiting local waters. 

 The Umbridce represent an archaic type, older than the Esotidce, 

 and evidently characteristic of an earlier fish fauna. Their 

 survival in forms so widely separated geographically is interest- 

 ingly suggestive to the student of distribution and descent. 



GENUS UMBRA (KRAMER) MULLER 



MUDFISHES 



Generic characters included in description of family. Size small; species 

 3, inhabiting fresh waters of the United States and Austria; one species 

 known from Illinois. 



UMBRA LIMI (KIRTLAND) 

 MUD-MINNOW; MUDFISH 



(Pi,., P. 211; MAP LX) 



Kirtland, 1840, Bost. J. Nat. Hist., Ill, 277 (Hydrargira). 



G., VI, 232; J. & G., 350; M. V., 87; J. & E., I, 623; N., 43 (Melanura); J., 52 (Mela- 

 nura); P., 71; F. P., I. 6, 73; L., 21. 



Length 4 inches; body oblong, compressed, caudal peduncle deep; depth 

 in length 3.9 to 5 3; greatest width of body about % its greatest depth; depth 

 caudal peduncle 1.3 to 1.6 in its length. Color of upper parts dull brownish 

 plive mottled with black; sides with about 14 indefinite narrow transverse 

 bars of dark color, the interspaces bluish forward; breast, belly, and under 

 sides of head yellowish; a large black blotch-like bar at end of caudal pe- 

 duncle; a black stripe across cheek and through eye to end of snout; fins plain 

 olive-green, the caudal somewhat darker at center. Head 3.3 to 3.8; width 

 of head 1.7 to 1.9 in its length; interorbital space nearly flat, 4.3 to 5.4; eye 

 3.8 to 5.2; nose 3.9 to 5; mouth rather large, maxillary reaching to middle of 

 orbit, 2.8 to 3.8 (usually about 3) in head; teeth on premaxillary, lower jaw, 

 vomer, and palatines; gill-membranes free from isthmus. Dorsal fin 14, 

 sometimes 15, inserted behind ventrals and behind middle of body; anal 8 or 

 9; caudal rounded; pectorals short, broad and round, 1.6 to 2 in head. Scales 

 35, transverse series 13 or 14;no lateral line;opercles with large scalesjscales 

 on opercles embedded. 



Mud-minnows are small fishes, few individuals exceeding 

 five or six inches in length. They are frequently mistaken by 

 fishermen for the young of the dogfish, from which, however, 

 they are very readily distinguished by the short dorsal fin. 

 They rest quietly upon the bottom much of the time, and when 



