178 Descriptive Zoology. 



its cartilaginous skeleton. The skin is also rough like that 

 of a shark ; but in addition to the separate scales that give 

 roughness, there are several rows of bony plates, each with 

 a central projecting point. These rows of scales are not 

 set close together, one row of large scales being along the 

 back, with rows of smaller scales along the sides. The 

 sturgeon has a projectile toothless mouth, and feeds along 

 the bottom, sucking up worms, larvae, etc., from the mud. 



The spoonbill catfish very much resembles a catfish, being 

 smooth-skinned, but has a long, paddle-shaped upper jaw 

 with which to stir up the mud from which it gets its food. 



The mudfish, or bowfin, is, in the Mississippi Valley, 

 commonly called the " dogfish," an unfortunate term that 



FIG. 114. MUDFISH; BOWFIN; GRINDLE. 



Dogfish (of Central States, but should not be confused with the shark called dogfish). 



is likely to confuse it with the shark called by the same 

 name. The mudfish, as the name implies, lives in shallow 

 water, and is a very voracious fish. It is more nearly like 

 the ordinary bony fishes than the other ganoids, having a 

 pretty complete bony skeleton. Its flesh is soft, and gen- 

 erally considered as wholly unfit for food, but of late it is 

 beginning to be used. In some waters of the Mississippi 

 system it is very abundant. 



These four fishes do not present many characteristics in 

 common, hence it is not strange that the authorities differ 

 greatly as to their classification. In the first place, it should 



