THE SILURUS GLANIS. 171 
range within the last century ; it is now of not un- 
common occurrence in the Lake of Constance, into 
which it was accidentally introduced by inundations ; 
and several instances are known of its capture in 
Holland, although it is evidently not indigenous to 
that country. 
THE SILURUS GLANIS OR WELS. 
The wels in general appearance has some simi- 
larity to the burbot; the head is large, broad, and 
depressed, as long as the trunk, which ordinarily is 
subcylindrical, but appears also very broad when the 
fish has filled its capacious stomach, or when the 
female is full of roe; the tail is compressed, and 
longer than the head and trunk together. The entire 
fish is destitute of scales, and covered with a smooth 
slippery skin like the eel. The snout is truncated, 
the mouth not cleft far backwards, but broad, with 
the lower jaw longest and very extensible. There are 
six barbels round the mouth, two of which, situated 
