26 



Those having teeth with grinding surfaces are herbivorous, 

 and those without these masticatory surfaces are carniv- 

 orous. The pharyngeal teeth of tlie suckers are larger 

 and more numerous than in the minnows, and may be 

 sharj), or more or less truncated. They feed upon vege- 

 table matter and micro-organisms extracted from the mud, 

 and some of them on thin-shelled, minute mollusks. 



The larger toothless fishes, as the sturgeons, whitefish, 

 mullets, etc., feed upon minute animal organisms, mostly 

 crustaceans. Some of the large toothless fishes, as the 

 shovel-nosed sturgeon, paddle-fish, and saw-fish, have the 

 snout prolonged into organs for stirring up the* mud or 

 sand of the bottom in order to obtain the small animal 

 forifis upon which they feed. The paddle-fish has the gill- 

 rakers developed into a beautiful straining appai'atus for 

 securing these minute cj eatures. The saw of the saw-fish 

 is not used, as has been frequently asserted, as a weapon 

 for disabling its prey for food, though it is used as a weap- 

 on of defense. Its use in ^^rocuring food is by stirring 

 up the mud or sand of the bottom, and the food, as in the 

 case of the paddle-fish and shovel-nosed sturgeon, is com- 

 posed of small forms. I have frequently observed schools 

 of half -grown saw-fishes feeding in shallow water by rak- 

 ing the bottom with their saws, which are well-fitted for 

 this purjiose. Their food seemed to be principally small 

 crustaceans and mollusks. 



Fishes with small, feeble, sub-equal teeth, as the herrings 

 {Clupeida)^ anchovies {Engraulidce), silversides {^Ather- 

 inidcB), etc., as we might imagine, feed upon minute or 

 microscopic invertebrate forms, mostly crustaceans, which 

 exist in countless myriads in both fresh and salt water. 



Fishes with bands or patches of villiform or brush-like 

 teeth, as the sunfishes {Centrai'diidcB), catfishes {Si'lu- 

 TidcB), striped basses {Labracince), etc., feed principally 

 on crawfish, crabs, shrimp, etc., insects, and occasionally 

 small fishes. The black bass is not, as popularly supposed. 



