CHARACTERISTICS OF VALUABLE MARINE FISHES 55 



one family. They are bottom fishes. There are two dorsal fins, 

 and long spines projecting from the bones of the gill-cover. In 

 the bull heads, one of which is the common fresh-water miller's 

 thumb, the skin is without scales and soft. The gurnards (Fig. 



FIG. 21. The Common or Grey Gurnard. 



21) are distinguished by their three fingers or legs on each side 

 of the body, and the bony covering of the head. In the sucker 

 fishes and gobies the throat fins are formed into a sucker, which 

 in the latter shows the original structure of the fins less altered 



FIG. 22. The Lump-sucker. 



than in the former, where the sucker is level with the skin. 

 These are all small shore fishes, except the lump-sucker (Fig. 22), 

 which is of no importance as a food fish. The dragonet, the 

 male of which (Fig. 23) is remarkable for its beautiful colouring 



