610 TELEOSTEI CHAP. 
rarious freshwater deposits in Europe as far back as the 
Oligocene. J. lepidotus, of which very perfect specimens have 
been found in the Upper Miocene beds of Oeningen in Baden, 
differs from the living species in its much larger scales and in 
the greater approximation of the ventral and anal fins, two 
characters in which it approaches Umbra. Only two species of 
the latter are known: U. crameri (“ Hundsfisch”), from the 
stagnant waters of Austria-Hungary, and U. limi (“ Mud-Fish”), 
living in swamps and ditches in Canada and the north-eastern 
United States, often remaining imbedded in the mud of prairie 
sloughs and bog-holes. 
Fic. 369.—Distribution of the Esocidae. 
Fam. 5. Dalliidae.—The genus Dallia, with a single species 
inhabiting the streams and ponds of Alaska and Siberia, is related 
to Umbra, but differs in the very thin and papery skeleton, with 
the post-temporal imperfectly ossified and the pectoral fin without 
pterygials or actinosts. The dorsal fin is far back and opposite 
to the anal, as in the Pike. The ventral fins are composed of 
three rays only, and the pectorals, which have a somewhat fleshy 
base, have as many as 36. The scales are extremely smail, and 
partly imbedded in the skin. The Black-Fish, D. pectoralis, 
abounds in Sphagnum ponds, feeding on plants and worms, and 
forming the chief food of the natives of some parts of Northern 
Alaska, where, with the exception of the Salmonids, it is the only 
freshwater Fish. Turner, its discoverer, says its vitality is extra- 
