350 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 
*■ Pectorals narrow, with few (12-15) rays; ventralraysG ; scalesmoderate. Umbra, 165. 
** Pectorals broad, with many (33-36) rays; ventral rays 3 ; scales small.. Dallia, 166. 
16.5.— UMBRA Muller. 
MiuJ-finlies. 
{Melanura Agassiz.) 
(Kramer; Miiller, Abhandl. Akad. Wiss. Wien, Berl. 1842, 188: type Umbra crameri 
MUller.) 
Body oblong, covered with cycloid scales of moderate size, without 
radiating strim; no lateral line. Head shortish, little depressed. Eye 
rather small. Cleft of mouth moderate. Ventral fins C-rayed, below 
or slightly in front of <lorsal; anal fin much shorter than dorsal. Pec- 
torals rather narrow, rounded, placed low, with 12-15 rays, which are 
much jointed. Caudal rounded. Preopercle and preorbital with mu- 
cous pores. Brauchiostegals 6. Gill-rakers short, thick. Size small. 
Two species, very similar to each other, inhabiting the waters of the 
United States and Austria. (Latin, umbra., a shade.) 
STl. U. lisni (Kirt.) Gthr. — Mud Minnow ; Dog-fish. 
Dark-green or olive, mottled, sides with irregular narrow pale bars, 
these often obscure or wanting; a distinct black bar at base of caudal ; 
whitish stripes sometimes present along the rows of scales. Head 3^ 
in length; deiMh 4^. B. G; P.14; D. 14; A. 8; Y. 0; Lat. 1. 35; L. 
transv. 15. L. 4 inches. Vermont to Minnesota and South Carolina. 
Abundant northward in weedy streams and ditches. “ A locality which 
with the water perfectly clear will appear destitute of fish will perhaps 
yield a number of mud-fish on stirring up the mud at the bottom and 
drawing a seine through it. Ditches in the jirairies of Wisconsin, or 
mere bog-holes, apparently aflbrding lodgment to nothing beyond tad- 
poles, may thus be found filled with Melanuras.^^ (Baird.) 
{ligdrarggra limi Kirtland, Bust. Journ. Nat. Hist, iii, 277 : Melanura annulata Ag. 
Am. Jomn. Sci. & Arts, 1854, 135: Umbra limi GUnther, vi, 232: Leuciscus pggmmis De 
Kay, New York Fauna, Fishes, 214 : Umbra pggmcca Jordan, Bull. U. S. Nat. Mus. x, 53 ; 
the eastern form, pggmcea, usually slightly differing in proportions.) 
166.— DAUUIA Bean. 
(Bean, Proc. U. S. Nat. Mus. 1870, 358: type Dallia pecioralis Bean.) 
Body oblong, covered with small, partly embedded cycloid scales; a 
trace of lateral line; a line of mucous tubes below eye. Eye small. 
Cleft of mouth moderate. Villiform or almost cardiform teeth on jaws, 
vomer, and palatines; those on iiremaxillaries enlarged. Ventrals in 
